diff --git a/.docker/ruby/Dockerfile b/.docker/ruby/Dockerfile
new file mode 100644
index 00000000..0b7cdad3
--- /dev/null
+++ b/.docker/ruby/Dockerfile
@@ -0,0 +1,30 @@
+FROM ruby:2.7
+
+RUN apt-get update -qq && apt-get install -y build-essential
+
+# for postgres
+RUN apt-get install -y libpq-dev
+
+# for nokogiri
+RUN apt-get install -y libxml2-dev libxslt1-dev
+
+# for images
+RUN apt-get install -y libmagickwand-dev imagemagick
+
+# for a JS runtime
+RUN curl -sL https://deb.nodesource.com/setup_6.x | bash -
+RUN apt-get install -y nodejs
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        postgresql-client \
+    && rm -rf /var/lib/apt/lists/*
+
+ENV APP_HOME /app
+RUN mkdir $APP_HOME
+WORKDIR $APP_HOME
+
+ADD Gemfile* $APP_HOME/
+RUN bundle install
+
+EXPOSE 3000
diff --git a/.ruby-version b/.ruby-version
index 338a5b5d..860487ca 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-2.6.6
+2.7.1
diff --git a/Gemfile b/Gemfile
index 70ae8baa..90b9c97f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,24 +1,24 @@
 source 'https://rubygems.org'
 source 'https://rails-assets.org'
 
-gem 'rails', '~> 4.2.11', '>= 4.2.11.1'
-gem 'rails-i18n'
+gem 'rails', '~> 5.2'
+gem 'rails-i18n', '~> 5.0'
 gem 'i18n-js', '= 3.0.0.rc10'
 
 gem 'pg'
 
-gem 'sass-rails', '~> 4.0.3'
+gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
-gem 'coffee-rails', '~> 4.1.0'
+gem 'coffee-rails', '~> 4.1'
 gem 'jquery-rails'
 gem 'turbolinks', '~> 2.5.3'
 gem 'jquery-turbolinks'
-gem 'jbuilder', '~> 2.2.4'
+gem 'jbuilder', '~> 2.10'
 gem 'sdoc', '~> 0.4.1', group: :doc
 
 gem 'bcrypt', '~> 3.1.7'
 
-gem 'haml', '~> 4.0'
+gem 'haml', '~> 5.0'
 gem 'bootstrap-sass', '~> 3.4.0'
 gem 'bootswatch-rails'
 gem 'sweetalert-rails'
@@ -26,11 +26,11 @@ gem 'will_paginate'
 gem 'will_paginate-bootstrap'
 gem 'devise', '~> 4.0'
 gem 'devise-i18n'
-gem 'devise-async', git: "https://github.com/mhfs/devise-async.git", ref: "devise-4.x" # TODO: bring this to 1.0 after rails5 upgrade
+gem 'devise-async'
 gem 'bootstrap_form'
 gem 'font-kit-rails'
 gem 'nprogress-rails'
-gem 'font-awesome-rails', '~> 4.3.0.0'
+gem 'font-awesome-rails', '~> 4.7.0'
 gem 'rails-assets-growl'
 gem 'rails-assets-jquery', '~> 2.2.0'
 gem "paperclip", "~> 4.2"
@@ -51,8 +51,7 @@ gem 'rails_admin'
 gem 'pghero'
 gem 'newrelic_rpm'
 
-gem 'sidekiq'
-gem 'sinatra', require: false
+gem 'sidekiq', "< 6" # remove version constraint once we have redis 5
 
 gem 'questiongenerator', git: 'https://github.com/retrospring/questiongenerator.git'
 
@@ -88,6 +87,11 @@ end
 group :development do
   gem 'capistrano', '~> 3.8', require: false
   gem 'capistrano-rails', require: false
+
+  gem 'rbnacl', '>= 3.2', '< 5.0', require: false
+  gem 'rbnacl-libsodium', require: false
+  gem 'bcrypt_pbkdf', '>= 1.0', '< 2.0', require: false
+  gem 'ed25519', require: false
 end
 
 group :production do
@@ -97,7 +101,7 @@ end
 group :development, :test do
   gem 'rake'
   gem 'puma'
-  gem 'rspec-rails', '~> 3.5'
+  gem 'rspec-rails', '~> 3.9'
   gem 'factory_girl_rails', require: false
   gem 'faker'
   gem 'capybara'
diff --git a/Gemfile.lock b/Gemfile.lock
index 75f11229..5f212824 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,11 +1,3 @@
-GIT
-  remote: https://github.com/mhfs/devise-async.git
-  revision: 177f6363a002f7ff28f1d289c8cab7ad8d9cb8c5
-  ref: devise-4.x
-  specs:
-    devise-async (0.10.2)
-      devise (>= 4.0)
-
 GIT
   remote: https://github.com/retrospring/questiongenerator.git
   revision: c5f8362ff769425d42a94b3a611731eadaa5e0ca
@@ -16,103 +8,117 @@ GEM
   remote: https://rubygems.org/
   remote: https://rails-assets.org/
   specs:
-    CFPropertyList (2.3.5)
-    actionmailer (4.2.11.1)
-      actionpack (= 4.2.11.1)
-      actionview (= 4.2.11.1)
-      activejob (= 4.2.11.1)
+    CFPropertyList (2.3.6)
+    actioncable (5.2.4.2)
+      actionpack (= 5.2.4.2)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailer (5.2.4.2)
+      actionpack (= 5.2.4.2)
+      actionview (= 5.2.4.2)
+      activejob (= 5.2.4.2)
       mail (~> 2.5, >= 2.5.4)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
-    actionpack (4.2.11.1)
-      actionview (= 4.2.11.1)
-      activesupport (= 4.2.11.1)
-      rack (~> 1.6)
-      rack-test (~> 0.6.2)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
+      rails-dom-testing (~> 2.0)
+    actionpack (5.2.4.2)
+      actionview (= 5.2.4.2)
+      activesupport (= 5.2.4.2)
+      rack (~> 2.0, >= 2.0.8)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (4.2.11.1)
-      activesupport (= 4.2.11.1)
+    actionview (5.2.4.2)
+      activesupport (= 5.2.4.2)
       builder (~> 3.1)
-      erubis (~> 2.7.0)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (4.2.11.1)
-      activesupport (= 4.2.11.1)
-      globalid (>= 0.3.0)
-    activemodel (4.2.11.1)
-      activesupport (= 4.2.11.1)
+    activejob (5.2.4.2)
+      activesupport (= 5.2.4.2)
+      globalid (>= 0.3.6)
+    activemodel (5.2.4.2)
+      activesupport (= 5.2.4.2)
+    activemodel-serializers-xml (1.0.2)
+      activemodel (> 5.x)
+      activesupport (> 5.x)
       builder (~> 3.1)
-    activerecord (4.2.11.1)
-      activemodel (= 4.2.11.1)
-      activesupport (= 4.2.11.1)
-      arel (~> 6.0)
-    activesupport (4.2.11.1)
-      i18n (~> 0.7)
+    activerecord (5.2.4.2)
+      activemodel (= 5.2.4.2)
+      activesupport (= 5.2.4.2)
+      arel (>= 9.0)
+    activestorage (5.2.4.2)
+      actionpack (= 5.2.4.2)
+      activerecord (= 5.2.4.2)
+      marcel (~> 0.3.1)
+    activesupport (5.2.4.2)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.5.1)
-      public_suffix (~> 2.0, >= 2.0.2)
-    airbrussh (1.1.2)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
+    airbrussh (1.4.0)
       sshkit (>= 1.6.1, != 1.7.0)
-    arel (6.0.4)
-    autoprefixer-rails (9.5.0)
+    arel (9.0.0)
+    autoprefixer-rails (9.7.6)
       execjs
-    bcrypt (3.1.12)
-    better_errors (2.1.1)
+    bcrypt (3.1.13)
+    bcrypt_pbkdf (1.0.1)
+    better_errors (2.6.0)
       coderay (>= 1.0.0)
-      erubis (>= 2.6.6)
+      erubi (>= 1.0.0)
       rack (>= 0.9.0)
-    binding_of_caller (0.7.2)
+    binding_of_caller (0.8.0)
       debug_inspector (>= 0.0.1)
     bootstrap-sass (3.4.1)
       autoprefixer-rails (>= 5.2.1)
       sassc (>= 2.0.0)
     bootstrap3-datetimepicker-rails (4.7.14)
       momentjs-rails (>= 2.8.1)
-    bootstrap_form (2.6.0)
+    bootstrap_form (4.4.0)
+      actionpack (>= 5.0)
+      activemodel (>= 5.0)
     bootswatch-rails (3.3.5)
       railties (>= 3.1)
-    brakeman (3.6.1)
+    brakeman (4.8.1)
     buftok (0.2.0)
-    builder (3.2.3)
-    byebug (9.0.6)
-    capistrano (3.8.0)
+    builder (3.2.4)
+    byebug (11.1.2)
+    capistrano (3.13.0)
       airbrussh (>= 1.0.0)
       i18n
       rake (>= 10.0.0)
       sshkit (>= 1.9.0)
-    capistrano-bundler (1.2.0)
+    capistrano-bundler (1.6.0)
       capistrano (~> 3.1)
-      sshkit (~> 1.2)
-    capistrano-rails (1.2.3)
+    capistrano-rails (1.4.0)
       capistrano (~> 3.1)
       capistrano-bundler (~> 1.1)
-    capybara (2.13.0)
+    capybara (3.32.1)
       addressable
-      mime-types (>= 1.16)
-      nokogiri (>= 1.3.3)
-      rack (>= 1.0.0)
-      rack-test (>= 0.5.4)
-      xpath (~> 2.0)
+      mini_mime (>= 0.1.3)
+      nokogiri (~> 1.8)
+      rack (>= 1.6.0)
+      rack-test (>= 0.6.3)
+      regexp_parser (~> 1.5)
+      xpath (~> 3.2)
     climate_control (0.2.0)
     cliver (0.3.2)
     cocaine (0.5.8)
       climate_control (>= 0.0.3, < 1.0)
-    coderay (1.1.1)
-    coffee-rails (4.1.1)
+    coderay (1.1.2)
+    coffee-rails (4.2.2)
       coffee-script (>= 2.2.0)
-      railties (>= 4.0.0, < 5.1.x)
+      railties (>= 4.0.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
     colorize (0.8.1)
-    concurrent-ruby (1.0.5)
-    connection_pool (2.2.1)
-    crass (1.0.4)
-    database_cleaner (1.5.3)
-    debug_inspector (0.0.2)
+    concurrent-ruby (1.1.6)
+    connection_pool (2.2.2)
+    crass (1.0.6)
+    database_cleaner (1.8.4)
+    debug_inspector (0.0.3)
     delayed_paperclip (3.0.1)
       activejob (>= 4.2)
       paperclip (>= 3.3)
@@ -122,44 +128,55 @@ GEM
       railties (>= 4.1.0)
       responders
       warden (~> 1.2.3)
-    devise-i18n (1.1.2)
+    devise-async (1.0.0)
+      activejob (>= 5.0)
+      devise (>= 4.0)
+    devise-i18n (1.9.1)
+      devise (>= 4.7.1)
     diff-lcs (1.3)
-    docile (1.1.5)
-    domain_name (0.5.20170223)
+    docile (1.3.2)
+    domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)
+    dry-inflector (0.2.0)
+    ed25519 (1.2.4)
     equalizer (0.0.11)
-    erubis (2.7.0)
+    erubi (1.9.0)
     excon (0.73.0)
     execjs (2.7.0)
-    factory_girl (4.8.0)
+    factory_girl (4.9.0)
       activesupport (>= 3.0.0)
-    factory_girl_rails (4.8.0)
-      factory_girl (~> 4.8.0)
+    factory_girl_rails (4.9.0)
+      factory_girl (~> 4.9.0)
       railties (>= 3.0.0)
     fake_email_validator (1.0.11)
       activemodel
       mail
-    faker (1.7.3)
-      i18n (~> 0.5)
-    faraday (0.11.0)
+    faker (2.2.1)
+      i18n (>= 0.8)
+    faraday (0.9.2)
       multipart-post (>= 1.2, < 3)
-    faraday_middleware (0.11.0.1)
-      faraday (>= 0.7.4, < 1.0)
-    ffi (1.10.0)
+    faraday_middleware (0.9.2)
+      faraday (>= 0.7.4, < 0.10)
+    ffi (1.12.2)
+    ffi-compiler (1.0.1)
+      ffi (>= 1.0.0)
+      rake
     fission (0.5.0)
       CFPropertyList (~> 2.2)
-    fog (1.40.0)
+    fog (1.41.0)
       fog-aliyun (>= 0.1.0)
       fog-atmos
       fog-aws (>= 0.6.0)
       fog-brightbox (~> 0.4)
       fog-cloudatcost (~> 0.1.0)
-      fog-core (~> 1.43)
+      fog-core (~> 1.45)
       fog-digitalocean (>= 0.3.0)
       fog-dnsimple (~> 1.0)
       fog-dynect (~> 0.0.2)
       fog-ecloud (~> 0.1)
       fog-google (<= 0.1.0)
+      fog-internet-archive
+      fog-joyent
       fog-json
       fog-local
       fog-openstack
@@ -180,36 +197,37 @@ GEM
       fog-xml (~> 0.1.1)
       ipaddress (~> 0.5)
       json (>= 1.8, < 2.0)
-    fog-aliyun (0.1.0)
-      fog-core (~> 1.27)
-      fog-json (~> 1.0)
+    fog-aliyun (0.3.8)
+      fog-core
+      fog-json
       ipaddress (~> 0.8)
       xml-simple (~> 1.1)
     fog-atmos (0.1.0)
       fog-core
       fog-xml
-    fog-aws (1.3.0)
+    fog-aws (2.0.1)
       fog-core (~> 1.38)
       fog-json (~> 1.0)
       fog-xml (~> 0.1)
       ipaddress (~> 0.8)
-    fog-brightbox (0.11.0)
-      fog-core (~> 1.22)
+    fog-brightbox (0.16.1)
+      dry-inflector
+      fog-core
       fog-json
-      inflecto (~> 0.0.2)
+      mime-types
     fog-cloudatcost (0.1.2)
       fog-core (~> 1.36)
       fog-json (~> 1.0)
       fog-xml (~> 0.1)
       ipaddress (~> 0.8)
-    fog-core (1.43.0)
+    fog-core (1.45.0)
       builder
-      excon (~> 0.49)
+      excon (~> 0.58)
       formatador (~> 0.2)
-    fog-digitalocean (0.3.0)
-      fog-core (~> 1.42)
-      fog-json (>= 1.0)
-      fog-xml (>= 0.1)
+    fog-digitalocean (0.4.0)
+      fog-core
+      fog-json
+      fog-xml
       ipaddress (>= 0.5)
     fog-dnsimple (1.0.0)
       fog-core (~> 1.38)
@@ -225,23 +243,30 @@ GEM
       fog-core
       fog-json
       fog-xml
-    fog-json (1.0.2)
-      fog-core (~> 1.0)
+    fog-internet-archive (0.0.1)
+      fog-core
+      fog-json
+      fog-xml
+    fog-joyent (0.0.1)
+      fog-core (~> 1.42)
+      fog-json (>= 1.0)
+    fog-json (1.2.0)
+      fog-core
       multi_json (~> 1.10)
-    fog-local (0.3.1)
-      fog-core (~> 1.27)
-    fog-openstack (0.1.20)
-      fog-core (>= 1.40)
+    fog-local (0.6.0)
+      fog-core (>= 1.27, < 3.0)
+    fog-openstack (0.3.10)
+      fog-core (>= 1.45, <= 2.1.0)
       fog-json (>= 1.0)
       ipaddress (>= 0.8)
-    fog-powerdns (0.1.1)
-      fog-core (~> 1.27)
-      fog-json (~> 1.0)
-      fog-xml (~> 0.1)
-    fog-profitbricks (3.0.0)
+    fog-powerdns (0.2.0)
+      fog-core
+      fog-json
+      fog-xml
+    fog-profitbricks (4.1.1)
       fog-core (~> 1.42)
       fog-json (~> 1.0)
-    fog-rackspace (0.1.4)
+    fog-rackspace (0.1.6)
       fog-core (>= 1.35)
       fog-json (>= 1.0)
       fog-xml (>= 0.1)
@@ -275,64 +300,67 @@ GEM
     fog-voxel (0.1.0)
       fog-core
       fog-xml
-    fog-vsphere (1.9.0)
+    fog-vsphere (3.3.0)
       fog-core
-      rbvmomi (~> 1.9)
-    fog-xenserver (0.3.0)
+      rbvmomi (>= 1.9, < 3)
+    fog-xenserver (1.0.0)
       fog-core
       fog-xml
+      xmlrpc
     fog-xml (0.1.3)
       fog-core
       nokogiri (>= 1.5.11, < 2.0.0)
-    font-awesome-rails (4.3.0.0)
-      railties (>= 3.2, < 5.0)
+    font-awesome-rails (4.7.0.5)
+      railties (>= 3.2, < 6.1)
     font-kit-rails (1.2.0)
       rails
-    foreman (0.84.0)
-      thor (~> 0.19.1)
+    foreman (0.87.1)
     formatador (0.2.5)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
-    guard (2.14.1)
+    guard (2.16.2)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
-      lumberjack (~> 1.0)
+      lumberjack (>= 1.0.12, < 2.0)
       nenv (~> 0.1)
       notiffany (~> 0.0)
       pry (>= 0.9.12)
       shellany (~> 0.0)
       thor (>= 0.18.1)
-    guard-brakeman (0.8.3)
+    guard-brakeman (0.8.6)
       brakeman (>= 2.1.1)
       guard (>= 2.0.0)
-    haml (4.0.7)
+      guard-compat (~> 1.0)
+    guard-compat (1.2.1)
+    haml (5.1.2)
+      temple (>= 0.8.0)
       tilt
     hashie (4.1.0)
-    hike (1.2.3)
-    http (2.2.1)
+    http (4.4.1)
       addressable (~> 2.3)
       http-cookie (~> 1.0)
-      http-form_data (~> 1.0.1)
-      http_parser.rb (~> 0.6.0)
+      http-form_data (~> 2.2)
+      http-parser (~> 1.2.0)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
-    http-form_data (1.0.1)
+    http-form_data (2.3.0)
+    http-parser (1.2.1)
+      ffi-compiler (>= 1.0, < 2.0)
     http_parser.rb (0.6.0)
-    httparty (0.14.0)
+    httparty (0.18.0)
+      mime-types (~> 3.0)
       multi_xml (>= 0.5.2)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
     i18n-js (3.0.0.rc10)
       i18n (~> 0.6)
-    inflecto (0.0.2)
     ipaddress (0.8.3)
-    jbuilder (2.2.16)
-      activesupport (>= 3.0.0, < 5)
-      multi_json (~> 1.2)
-    jquery-minicolors-rails (2.2.3.1)
+    jbuilder (2.10.0)
+      activesupport (>= 5.0.0)
+    jquery-minicolors-rails (2.2.6.2)
       jquery-rails
       rails (>= 3.2.8)
-    jquery-rails (4.3.1)
+    jquery-rails (4.3.5)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
@@ -354,52 +382,54 @@ GEM
       activerecord
       kaminari-core (= 1.2.0)
     kaminari-core (1.2.0)
-    kgio (2.11.0)
-    launchy (2.4.3)
-      addressable (~> 2.3)
-    letter_opener (1.4.1)
+    kgio (2.11.3)
+    launchy (2.5.0)
+      addressable (~> 2.7)
+    letter_opener (1.7.0)
       launchy (~> 2.2)
-    listen (3.1.5)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
-      ruby_dep (~> 1.2)
+    listen (3.2.1)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
     loofah (2.5.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
-    lumberjack (1.0.11)
-    mail (2.6.4)
-      mime-types (>= 1.16, < 4)
+    lumberjack (1.2.4)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    marcel (0.3.3)
+      mimemagic (~> 0.3.2)
     memoizable (0.4.2)
       thread_safe (~> 0.3, >= 0.3.1)
-    method_source (0.8.2)
-    mime-types (3.1)
+    method_source (1.0.0)
+    mime-types (3.3.1)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2016.0521)
-    mimemagic (0.3.0)
+    mime-types-data (3.2019.1009)
+    mimemagic (0.3.4)
+    mini_mime (1.0.2)
     mini_portile2 (2.4.0)
-    minitest (5.11.3)
-    momentjs-rails (2.17.1)
+    minitest (5.14.0)
+    momentjs-rails (2.20.1)
       railties (>= 3.1)
-    multi_json (1.12.1)
+    multi_json (1.14.1)
     multi_xml (0.6.0)
-    multipart-post (2.0.0)
+    multipart-post (2.1.1)
     naught (1.1.0)
     nenv (0.3.0)
     nested_form (0.3.2)
-    net-scp (1.2.1)
-      net-ssh (>= 2.6.5)
-    net-ssh (4.1.0)
-    newrelic_rpm (4.2.0.334)
+    net-scp (2.0.0)
+      net-ssh (>= 2.6.5, < 6.0.0)
+    net-ssh (5.2.0)
+    newrelic_rpm (6.10.0.364)
     nio4r (2.5.2)
     nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
-    nokogumbo (2.0.1)
+    nokogumbo (2.0.2)
       nokogiri (~> 1.8, >= 1.8.4)
-    notiffany (0.1.1)
+    notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
     nprogress-rails (0.2.0.2)
-    oauth (0.5.1)
+    oauth (0.5.4)
     omniauth (1.9.1)
       hashie (>= 3.4.6)
       rack (>= 1.6.2, < 3)
@@ -412,228 +442,234 @@ GEM
     omniauth-twitter (1.4.0)
       omniauth-oauth (~> 1.1)
       rack
+    optimist (3.0.0)
     orm_adapter (0.5.0)
-    paperclip (4.3.7)
+    paperclip (4.2.4)
       activemodel (>= 3.2.0)
       activesupport (>= 3.2.0)
       cocaine (~> 0.5.5)
       mime-types
-      mimemagic (= 0.3.0)
-    pg (0.20.0)
-    pghero (1.6.4)
-      activerecord
-    poltergeist (1.14.0)
-      capybara (~> 2.1)
+    pg (1.2.3)
+    pghero (2.4.2)
+      activerecord (>= 5)
+    poltergeist (1.18.1)
+      capybara (>= 2.1, < 4)
       cliver (~> 0.3.1)
       websocket-driver (>= 0.2.0)
-    pry (0.10.4)
-      coderay (~> 1.1.0)
-      method_source (~> 0.8.1)
-      slop (~> 3.4)
-    public_suffix (2.0.5)
+    pry (0.13.1)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
+    public_suffix (4.0.4)
     puma (4.3.3)
       nio4r (~> 2.0)
-    rack (1.6.13)
+    rack (2.0.9)
     rack-pjax (1.1.0)
       nokogiri (~> 1.5)
       rack (>= 1.1)
-    rack-protection (1.5.5)
+    rack-protection (2.0.8.1)
       rack
-    rack-test (0.6.3)
-      rack (>= 1.0)
-    rails (4.2.11.1)
-      actionmailer (= 4.2.11.1)
-      actionpack (= 4.2.11.1)
-      actionview (= 4.2.11.1)
-      activejob (= 4.2.11.1)
-      activemodel (= 4.2.11.1)
-      activerecord (= 4.2.11.1)
-      activesupport (= 4.2.11.1)
-      bundler (>= 1.3.0, < 2.0)
-      railties (= 4.2.11.1)
-      sprockets-rails
-    rails-assets-growl (1.3.2)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (5.2.4.2)
+      actioncable (= 5.2.4.2)
+      actionmailer (= 5.2.4.2)
+      actionpack (= 5.2.4.2)
+      actionview (= 5.2.4.2)
+      activejob (= 5.2.4.2)
+      activemodel (= 5.2.4.2)
+      activerecord (= 5.2.4.2)
+      activestorage (= 5.2.4.2)
+      activesupport (= 5.2.4.2)
+      bundler (>= 1.3.0)
+      railties (= 5.2.4.2)
+      sprockets-rails (>= 2.0.0)
+    rails-assets-growl (1.3.5)
       rails-assets-jquery
     rails-assets-jquery (2.2.4)
-    rails-deprecated_sanitizer (1.0.3)
-      activesupport (>= 4.2.0.alpha)
-    rails-dom-testing (1.0.9)
-      activesupport (>= 4.2.0, < 5.0)
-      nokogiri (~> 1.6)
-      rails-deprecated_sanitizer (>= 1.0.1)
-    rails-html-sanitizer (1.0.4)
-      loofah (~> 2.2, >= 2.2.2)
-    rails-i18n (4.0.9)
-      i18n (~> 0.7)
-      railties (~> 4.0)
-    rails_admin (1.4.3)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    rails-i18n (5.1.3)
+      i18n (>= 0.7, < 2)
+      railties (>= 5.0, < 6)
+    rails_admin (2.0.2)
+      activemodel-serializers-xml (>= 1.0)
       builder (~> 3.1)
-      coffee-rails (~> 4.0)
-      font-awesome-rails (>= 3.0, < 5)
       haml (>= 4.0, < 6)
       jquery-rails (>= 3.0, < 5)
       jquery-ui-rails (>= 5.0, < 7)
       kaminari (>= 0.14, < 2.0)
       nested_form (~> 0.3)
       rack-pjax (>= 0.7)
-      rails (>= 4.0, < 6)
+      rails (>= 5.0, < 7)
       remotipart (~> 1.3)
-      sass-rails (>= 4.0, < 6)
-    railties (4.2.11.1)
-      actionpack (= 4.2.11.1)
-      activesupport (= 4.2.11.1)
+      sassc-rails (>= 1.3, < 3)
+    railties (5.2.4.2)
+      actionpack (= 5.2.4.2)
+      activesupport (= 5.2.4.2)
+      method_source
       rake (>= 0.8.7)
-      thor (>= 0.18.1, < 2.0)
-    raindrops (0.18.0)
+      thor (>= 0.19.0, < 2.0)
+    raindrops (0.19.1)
     rake (13.0.1)
-    rb-fsevent (0.9.8)
-    rb-inotify (0.9.8)
-      ffi (>= 0.5.0)
-    rbvmomi (1.10.0)
+    rb-fsevent (0.10.3)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
+    rbnacl (4.0.2)
+      ffi
+    rbnacl-libsodium (1.0.16)
+      rbnacl (>= 3.0.1)
+    rbvmomi (2.4.1)
       builder (~> 3.0)
       json (>= 1.8)
       nokogiri (~> 1.5)
-      trollop (~> 2.1)
+      optimist (~> 3.0)
     rdoc (4.3.0)
-    redcarpet (3.4.0)
-    redis (3.3.3)
+    redcarpet (3.5.0)
+    redis (4.1.3)
+    regexp_parser (1.7.0)
     remotipart (1.4.4)
-    responders (2.4.1)
-      actionpack (>= 4.2.0, < 6.0)
-      railties (>= 4.2.0, < 6.0)
-    rollbar (2.14.1)
-      multi_json
-    rspec-core (3.5.4)
-      rspec-support (~> 3.5.0)
-    rspec-expectations (3.5.0)
+    responders (3.0.0)
+      actionpack (>= 5.0)
+      railties (>= 5.0)
+    rollbar (2.24.0)
+    rspec-core (3.9.1)
+      rspec-support (~> 3.9.1)
+    rspec-expectations (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.5.0)
-    rspec-mocks (3.5.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.5.0)
-    rspec-rails (3.5.2)
+      rspec-support (~> 3.9.0)
+    rspec-rails (3.9.1)
       actionpack (>= 3.0)
       activesupport (>= 3.0)
       railties (>= 3.0)
-      rspec-core (~> 3.5.0)
-      rspec-expectations (~> 3.5.0)
-      rspec-mocks (~> 3.5.0)
-      rspec-support (~> 3.5.0)
-    rspec-support (3.5.0)
-    ruby-progressbar (1.8.1)
-    ruby_dep (1.5.0)
-    sanitize (5.0.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.2)
+    ruby-progressbar (1.10.1)
+    sanitize (5.1.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.8.0)
       nokogumbo (~> 2.0)
-    sass (3.2.19)
-    sass-rails (4.0.5)
-      railties (>= 4.0.0, < 5.0)
-      sass (~> 3.2.2)
-      sprockets (~> 2.8, < 3.0)
-      sprockets-rails (~> 2.0)
-    sassc (2.0.1)
+    sass (3.7.4)
+      sass-listen (~> 4.0.0)
+    sass-listen (4.0.0)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
+    sass-rails (5.1.0)
+      railties (>= 5.2.0)
+      sass (~> 3.1)
+      sprockets (>= 2.8, < 4.0)
+      sprockets-rails (>= 2.0, < 4.0)
+      tilt (>= 1.1, < 3)
+    sassc (2.3.0)
       ffi (~> 1.9)
-      rake
+    sassc-rails (2.1.2)
+      railties (>= 4.0.0)
+      sassc (>= 2.0)
+      sprockets (> 3.0)
+      sprockets-rails
+      tilt
     sdoc (0.4.2)
       json (~> 1.7, >= 1.7.7)
       rdoc (~> 4.0)
     shellany (0.0.1)
-    sidekiq (4.2.10)
-      concurrent-ruby (~> 1.0)
-      connection_pool (~> 2.2, >= 2.2.0)
+    sidekiq (5.2.8)
+      connection_pool (~> 2.2, >= 2.2.2)
+      rack (< 2.1.0)
       rack-protection (>= 1.5.0)
-      redis (~> 3.2, >= 3.2.1)
+      redis (>= 3.3.5, < 5)
     simple_oauth (0.3.1)
-    simplecov (0.14.1)
-      docile (~> 1.1.0)
-      json (>= 1.8, < 3)
-      simplecov-html (~> 0.10.0)
-    simplecov-html (0.10.0)
-    simplecov-json (0.2)
+    simplecov (0.18.5)
+      docile (~> 1.1)
+      simplecov-html (~> 0.11)
+    simplecov-html (0.12.2)
+    simplecov-json (0.2.1)
       json
       simplecov
     simplecov-rcov (0.2.3)
       simplecov (>= 0.4.1)
-    sinatra (1.4.8)
-      rack (~> 1.5)
-      rack-protection (~> 1.4)
-      tilt (>= 1.3, < 3)
-    slop (3.6.0)
     spring (1.3.6)
-    sprockets (2.12.5)
-      hike (~> 1.2)
-      multi_json (~> 1.0)
-      rack (~> 1.0)
-      tilt (~> 1.1, != 1.3.0)
-    sprockets-rails (2.3.3)
-      actionpack (>= 3.0)
-      activesupport (>= 3.0)
-      sprockets (>= 2.8, < 4.0)
-    sshkit (1.13.1)
+    sprockets (3.7.2)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
+    sprockets-rails (3.2.1)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
+    sshkit (1.21.0)
       net-scp (>= 1.1.2)
       net-ssh (>= 2.8.0)
     sweetalert-rails (1.1.3)
       railties (>= 3.1.0)
-    thor (0.19.4)
+    temple (0.8.2)
+    thor (1.0.1)
     thread_safe (0.3.6)
-    tilt (1.4.1)
+    tilt (2.0.10)
     tiny-color-rails (0.0.2)
       railties (>= 3.0)
-    trollop (2.1.2)
-    tumblr_client (0.8.2)
-      faraday (>= 0.8)
-      faraday_middleware (>= 0.8)
+    tumblr_client (0.8.5)
+      faraday (~> 0.9.0)
+      faraday_middleware (~> 0.9.0)
       json
       mime-types
       oauth
       simple_oauth
-    turbolinks (2.5.3)
+    turbolinks (2.5.4)
       coffee-rails
     twemoji-rails (1.2.1.3)
       railties (>= 3.0.0)
-    twitter (6.1.0)
-      addressable (~> 2.5)
+    twitter (7.0.0)
+      addressable (~> 2.3)
       buftok (~> 0.2.0)
-      equalizer (= 0.0.11)
-      faraday (~> 0.11.0)
-      http (~> 2.1)
+      equalizer (~> 0.0.11)
+      http (~> 4.0)
+      http-form_data (~> 2.0)
       http_parser.rb (~> 0.6.0)
-      memoizable (~> 0.4.2)
-      naught (~> 1.1)
-      simple_oauth (~> 0.3.1)
-    tzinfo (1.2.5)
+      memoizable (~> 0.4.0)
+      multipart-post (~> 2.0)
+      naught (~> 1.0)
+      simple_oauth (~> 0.3.0)
+    tzinfo (1.2.7)
       thread_safe (~> 0.1)
-    uglifier (3.1.12)
+    uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
     unf (0.1.4)
       unf_ext
-    unf_ext (0.0.7.2)
-    unicorn (5.2.0)
+    unf_ext (0.0.7.7)
+    unicorn (5.5.4)
       kgio (~> 2.6)
       raindrops (~> 0.7)
-    warden (1.2.7)
-      rack (>= 1.0)
+    warden (1.2.8)
+      rack (>= 2.0.6)
     web-console (2.3.0)
       activemodel (>= 4.0)
       binding_of_caller (>= 0.7.2)
       railties (>= 4.0)
       sprockets-rails (>= 2.0, < 4.0)
-    websocket-driver (0.6.5)
+    websocket-driver (0.7.1)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.2)
-    will_paginate (3.1.5)
-    will_paginate-bootstrap (1.0.1)
+    websocket-extensions (0.1.4)
+    will_paginate (3.3.0)
+    will_paginate-bootstrap (1.0.2)
       will_paginate (>= 3.0.3)
     xml-simple (1.1.5)
-    xpath (2.0.0)
-      nokogiri (~> 1.3)
+    xmlrpc (0.3.0)
+    xpath (3.2.0)
+      nokogiri (~> 1.8)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   bcrypt (~> 3.1.7)
+  bcrypt_pbkdf (>= 1.0, < 2.0)
   better_errors
   bootstrap-sass (~> 3.4.0)
   bootstrap3-datetimepicker-rails (~> 4.7.14)
@@ -644,26 +680,27 @@ DEPENDENCIES
   capistrano (~> 3.8)
   capistrano-rails
   capybara
-  coffee-rails (~> 4.1.0)
+  coffee-rails (~> 4.1)
   colorize
   database_cleaner
   delayed_paperclip
   devise (~> 4.0)
-  devise-async!
+  devise-async
   devise-i18n
+  ed25519
   factory_girl_rails
   fake_email_validator
   faker
   fog
   fog-aws
-  font-awesome-rails (~> 4.3.0.0)
+  font-awesome-rails (~> 4.7.0)
   font-kit-rails
   foreman
   guard-brakeman
-  haml (~> 4.0)
+  haml (~> 5.0)
   httparty
   i18n-js (= 3.0.0.rc10)
-  jbuilder (~> 2.2.4)
+  jbuilder (~> 2.10)
   jquery-minicolors-rails
   jquery-rails
   jquery-turbolinks
@@ -680,25 +717,26 @@ DEPENDENCIES
   poltergeist
   puma
   questiongenerator!
-  rails (~> 4.2.11, >= 4.2.11.1)
+  rails (~> 5.2)
   rails-assets-growl
   rails-assets-jquery (~> 2.2.0)
-  rails-i18n
+  rails-i18n (~> 5.0)
   rails_admin
   rake
+  rbnacl (>= 3.2, < 5.0)
+  rbnacl-libsodium
   redcarpet
   redis
   rollbar
-  rspec-rails (~> 3.5)
+  rspec-rails (~> 3.9)
   ruby-progressbar
   sanitize
-  sass-rails (~> 4.0.3)
+  sass-rails (~> 5.0)
   sdoc (~> 0.4.1)
-  sidekiq
+  sidekiq (< 6)
   simplecov
   simplecov-json
   simplecov-rcov
-  sinatra
   spring (~> 1.3.5)
   sweetalert-rails
   tiny-color-rails
@@ -713,4 +751,4 @@ DEPENDENCIES
   will_paginate-bootstrap
 
 BUNDLED WITH
-   1.17.3
+   2.1.4
diff --git a/app/controllers/ajax/subscription_controller.rb b/app/controllers/ajax/subscription_controller.rb
index aaca19bb..746bcf48 100644
--- a/app/controllers/ajax/subscription_controller.rb
+++ b/app/controllers/ajax/subscription_controller.rb
@@ -1,5 +1,5 @@
 class Ajax::SubscriptionController < ApplicationController
-  before_filter :authenticate_user!
+  before_action :authenticate_user!
   rescue_from(ActionController::ParameterMissing) do |param_miss_ex|
     @status = :parameter_error
     @message = I18n.t('messages.parameter_error', parameter: param_miss_ex.param.capitalize)
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index ef5ee974..ccc1e3f9 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -3,9 +3,9 @@ class ApplicationController < ActionController::Base
   # For APIs, you may want to use :null_session instead.
   protect_from_forgery with: :exception
 
-  before_filter :configure_permitted_parameters, if: :devise_controller?
-  before_filter :check_locale
-  before_filter :banned?
+  before_action :configure_permitted_parameters, if: :devise_controller?
+  before_action :check_locale
+  before_action :banned?
 
   # check if user wants to read
   def check_locale
diff --git a/app/controllers/discover_controller.rb b/app/controllers/discover_controller.rb
index daeb7536..3f7d0c41 100644
--- a/app/controllers/discover_controller.rb
+++ b/app/controllers/discover_controller.rb
@@ -1,5 +1,5 @@
 class DiscoverController < ApplicationController
-  before_filter :authenticate_user!
+  before_action :authenticate_user!
 
   def index
     unless APP_CONFIG.dig(:features, :discover, :enabled) || current_user.mod?
diff --git a/app/controllers/group_controller.rb b/app/controllers/group_controller.rb
index 7c3eb2c1..7fc45a42 100644
--- a/app/controllers/group_controller.rb
+++ b/app/controllers/group_controller.rb
@@ -1,5 +1,5 @@
 class GroupController < ApplicationController
-  before_filter :authenticate_user!
+  before_action :authenticate_user!
 
   def index
     @group = current_user.groups.find_by_name!(params[:group_name])
diff --git a/app/controllers/inbox_controller.rb b/app/controllers/inbox_controller.rb
index 63ffa80f..5b40b455 100644
--- a/app/controllers/inbox_controller.rb
+++ b/app/controllers/inbox_controller.rb
@@ -1,5 +1,5 @@
 class InboxController < ApplicationController
-  before_filter :authenticate_user!
+  before_action :authenticate_user!
 
   def show
     @inbox = Inbox.where(user: current_user)
diff --git a/app/controllers/moderation_controller.rb b/app/controllers/moderation_controller.rb
index 98b62c5f..dd23ec67 100644
--- a/app/controllers/moderation_controller.rb
+++ b/app/controllers/moderation_controller.rb
@@ -1,5 +1,5 @@
 class ModerationController < ApplicationController
-  before_filter :authenticate_user!
+  before_action :authenticate_user!
 
   def index
     @type = params[:type]
diff --git a/app/controllers/notifications_controller.rb b/app/controllers/notifications_controller.rb
index 32861e64..8e824ebc 100644
--- a/app/controllers/notifications_controller.rb
+++ b/app/controllers/notifications_controller.rb
@@ -1,5 +1,5 @@
 class NotificationsController < ApplicationController
-  before_filter :authenticate_user!
+  before_action :authenticate_user!
 
   def index
     @type = params[:type]
diff --git a/app/controllers/public_controller.rb b/app/controllers/public_controller.rb
index 9ea76e76..d5b8af94 100644
--- a/app/controllers/public_controller.rb
+++ b/app/controllers/public_controller.rb
@@ -1,5 +1,5 @@
 class PublicController < ApplicationController
-  before_filter :authenticate_user!
+  before_action :authenticate_user!
 
   def index
     @timeline = Answer.joins(:user).where(users: { privacy_allow_public_timeline: true }).all.reverse_order.paginate(page: params[:page])
diff --git a/app/controllers/user_controller.rb b/app/controllers/user_controller.rb
index 104062c6..acebb416 100644
--- a/app/controllers/user_controller.rb
+++ b/app/controllers/user_controller.rb
@@ -1,7 +1,7 @@
 class UserController < ApplicationController
   include ThemeHelper
 
-  before_filter :authenticate_user!, only: %w(edit update edit_privacy update_privacy edit_theme update_theme preview_theme delete_theme data export begin_export)
+  before_action :authenticate_user!, only: %w(edit update edit_privacy update_privacy edit_theme update_theme preview_theme delete_theme data export begin_export)
 
   def show
     @user = User.where('LOWER(screen_name) = ?', params[:username].downcase).first!
diff --git a/app/helpers/theme_helper.rb b/app/helpers/theme_helper.rb
index ea9ba8c5..1202588c 100644
--- a/app/helpers/theme_helper.rb
+++ b/app/helpers/theme_helper.rb
@@ -2,7 +2,7 @@ module ThemeHelper
   def render_theme_with_context(context = {})
     klass = Class.new do
       def initialize(hash = {})
-        if hash.is_a? ActiveRecord::Base
+        if hash.is_a? ApplicationRecord
           x = [
             :primary_color, :primary_text,
             :danger_color, :danger_text,
@@ -23,7 +23,7 @@ module ThemeHelper
           end
         elsif hash.is_a? Hash
           hash.each do |k, v|
-            next unless v.is_a? Fixnum
+            next unless v.is_a? Integer
 
             self.instance_variable_set "@#{k}", ('#' + ('0000000' + hash[k].to_s(16))[-6, 6])
           end
diff --git a/app/models/answer.rb b/app/models/answer.rb
index 25ffc23a..652e24d8 100644
--- a/app/models/answer.rb
+++ b/app/models/answer.rb
@@ -1,4 +1,4 @@
-class Answer < ActiveRecord::Base
+class Answer < ApplicationRecord
   belongs_to :user
   belongs_to :question
   has_many :comments, dependent: :destroy
diff --git a/app/models/application_record.rb b/app/models/application_record.rb
new file mode 100644
index 00000000..71fbba5b
--- /dev/null
+++ b/app/models/application_record.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+class ApplicationRecord < ActiveRecord::Base
+  self.abstract_class = true
+end
diff --git a/app/models/comment.rb b/app/models/comment.rb
index 94059387..1392067c 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -1,4 +1,4 @@
-class Comment < ActiveRecord::Base
+class Comment < ApplicationRecord
   belongs_to :user
   belongs_to :answer
   validates :user_id, presence: true
diff --git a/app/models/comment_smile.rb b/app/models/comment_smile.rb
index 8c116723..915089b1 100644
--- a/app/models/comment_smile.rb
+++ b/app/models/comment_smile.rb
@@ -1,4 +1,4 @@
-class CommentSmile < ActiveRecord::Base
+class CommentSmile < ApplicationRecord
   belongs_to :user
   belongs_to :comment
   validates :user_id, presence: true, uniqueness: { scope: :comment_id, message: "already smiled comment" }
diff --git a/app/models/group.rb b/app/models/group.rb
index 68ad2e29..c7fbb9ad 100644
--- a/app/models/group.rb
+++ b/app/models/group.rb
@@ -1,4 +1,4 @@
-class Group < ActiveRecord::Base
+class Group < ApplicationRecord
   belongs_to :user
   has_many :group_members, dependent: :destroy
 
diff --git a/app/models/group_member.rb b/app/models/group_member.rb
index 0163e2c0..5bdf6dc0 100644
--- a/app/models/group_member.rb
+++ b/app/models/group_member.rb
@@ -1,4 +1,4 @@
-class GroupMember < ActiveRecord::Base
+class GroupMember < ApplicationRecord
   belongs_to :user
   belongs_to :group
 end
diff --git a/app/models/inbox.rb b/app/models/inbox.rb
index 0cea150b..458e9d63 100644
--- a/app/models/inbox.rb
+++ b/app/models/inbox.rb
@@ -1,4 +1,4 @@
-class Inbox < ActiveRecord::Base
+class Inbox < ApplicationRecord
   belongs_to :user
   belongs_to :question
 
diff --git a/app/models/moderation_comment.rb b/app/models/moderation_comment.rb
index da534d5c..d0baa654 100644
--- a/app/models/moderation_comment.rb
+++ b/app/models/moderation_comment.rb
@@ -1,4 +1,4 @@
-class ModerationComment < ActiveRecord::Base
+class ModerationComment < ApplicationRecord
   belongs_to :user
   belongs_to :report
   validates :user_id, presence: true
diff --git a/app/models/moderation_vote.rb b/app/models/moderation_vote.rb
index 6e12c832..14f70bf0 100644
--- a/app/models/moderation_vote.rb
+++ b/app/models/moderation_vote.rb
@@ -1,4 +1,4 @@
-class ModerationVote < ActiveRecord::Base
+class ModerationVote < ApplicationRecord
   belongs_to :user
   belongs_to :report
   validates :user_id, presence: true
diff --git a/app/models/notification.rb b/app/models/notification.rb
index d93e6821..18d29bd2 100644
--- a/app/models/notification.rb
+++ b/app/models/notification.rb
@@ -1,4 +1,4 @@
-class Notification < ActiveRecord::Base
+class Notification < ApplicationRecord
   belongs_to :recipient, class_name: 'User'
   belongs_to :target, polymorphic: true
 
diff --git a/app/models/question.rb b/app/models/question.rb
index adc95c59..29146367 100644
--- a/app/models/question.rb
+++ b/app/models/question.rb
@@ -1,4 +1,4 @@
-class Question < ActiveRecord::Base
+class Question < ApplicationRecord
   belongs_to :user
   has_many :answers, dependent: :destroy
   has_many :inboxes, dependent: :destroy
diff --git a/app/models/relationship.rb b/app/models/relationship.rb
index 2142276f..5ce6ac98 100644
--- a/app/models/relationship.rb
+++ b/app/models/relationship.rb
@@ -1,4 +1,4 @@
-class Relationship < ActiveRecord::Base
+class Relationship < ApplicationRecord
   belongs_to :source, class_name: 'User'
   belongs_to :target, class_name: 'User'
   validates :source_id, presence: true
diff --git a/app/models/report.rb b/app/models/report.rb
index a185bb48..9ed86152 100644
--- a/app/models/report.rb
+++ b/app/models/report.rb
@@ -1,4 +1,4 @@
-class Report < ActiveRecord::Base
+class Report < ApplicationRecord
   belongs_to :user
   has_many :moderation_votes, dependent: :destroy
   has_many :moderation_comments, dependent: :destroy
diff --git a/app/models/service.rb b/app/models/service.rb
index 5f924544..46bd234a 100644
--- a/app/models/service.rb
+++ b/app/models/service.rb
@@ -1,4 +1,4 @@
-class Service < ActiveRecord::Base
+class Service < ApplicationRecord
   attr_accessor :provider, :info
 
   belongs_to :user
diff --git a/app/models/smile.rb b/app/models/smile.rb
index 566c3bcc..2090cac0 100644
--- a/app/models/smile.rb
+++ b/app/models/smile.rb
@@ -1,4 +1,4 @@
-class Smile < ActiveRecord::Base
+class Smile < ApplicationRecord
   belongs_to :user
   belongs_to :answer
   validates :user_id, presence: true, uniqueness: { scope: :answer_id, message: "already smiled answer" }
diff --git a/app/models/subscription.rb b/app/models/subscription.rb
index c5065765..bab3bf39 100644
--- a/app/models/subscription.rb
+++ b/app/models/subscription.rb
@@ -1,4 +1,4 @@
-class Subscription < ActiveRecord::Base
+class Subscription < ApplicationRecord
   belongs_to :user
   belongs_to :answer
 
diff --git a/app/models/theme.rb b/app/models/theme.rb
index 5e6ddbc4..74700a54 100644
--- a/app/models/theme.rb
+++ b/app/models/theme.rb
@@ -1,4 +1,4 @@
-class Theme < ActiveRecord::Base
+class Theme < ApplicationRecord
   include ThemeHelper
 
   belongs_to :user
diff --git a/app/models/user.rb b/app/models/user.rb
index 18a508dd..43e88e4f 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,4 +1,4 @@
-class User < ActiveRecord::Base
+class User < ApplicationRecord
   # Include default devise modules. Others available are:
   # :confirmable, :lockable, :timeoutable and :omniauthable
   devise :database_authenticatable, :async, :registerable,
diff --git a/app/views/inbox/show.html.haml b/app/views/inbox/show.html.haml
index a8b2648a..45c62ba0 100644
--- a/app/views/inbox/show.html.haml
+++ b/app/views/inbox/show.html.haml
@@ -22,4 +22,4 @@
       = render 'inbox/sidebar'
 
 = render "shared/links"
-- @inbox.update_all(new: false)
+- Inbox.where(id: @inbox.ids).update_all(new: false)
diff --git a/app/views/user/data.html.haml b/app/views/user/data.html.haml
index 4db3efbe..9cff91a2 100644
--- a/app/views/user/data.html.haml
+++ b/app/views/user/data.html.haml
@@ -17,7 +17,7 @@
 
             %p.data-heading Display name
             %p.text-muted
-              - if current_user.display_name.empty?
+              - if current_user.display_name.blank?
                 None set!
               - else
                 = current_user.display_name
diff --git a/bin/rails b/bin/rails
index 5191e692..07396602 100755
--- a/bin/rails
+++ b/bin/rails
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
-APP_PATH = File.expand_path('../../config/application', __FILE__)
+APP_PATH = File.expand_path('../config/application', __dir__)
 require_relative '../config/boot'
 require 'rails/commands'
diff --git a/bin/setup b/bin/setup
index acdb2c13..e620b4da 100755
--- a/bin/setup
+++ b/bin/setup
@@ -1,29 +1,34 @@
 #!/usr/bin/env ruby
 require 'pathname'
+require 'fileutils'
+include FileUtils
 
 # path to your application root.
-APP_ROOT = Pathname.new File.expand_path('../../',  __FILE__)
+APP_ROOT = Pathname.new File.expand_path('../../', __FILE__)
 
-Dir.chdir APP_ROOT do
+def system!(*args)
+  system(*args) || abort("\n== Command #{args} failed ==")
+end
+
+chdir APP_ROOT do
   # This script is a starting point to setup your application.
-  # Add necessary setup steps to this file:
+  # Add necessary setup steps to this file.
 
-  puts "== Installing dependencies =="
-  system "gem install bundler --conservative"
-  system "bundle check || bundle install"
+  puts '== Installing dependencies =='
+  system! 'gem install bundler --conservative'
+  system('bundle check') || system!('bundle install')
 
   # puts "\n== Copying sample files =="
-  # unless File.exist?("config/database.yml")
-  #   system "cp config/database.yml.sample config/database.yml"
+  # unless File.exist?('config/database.yml')
+  #   cp 'config/database.yml.sample', 'config/database.yml'
   # end
 
   puts "\n== Preparing database =="
-  system "bin/rake db:setup"
+  system! 'bin/rails db:setup'
 
   puts "\n== Removing old logs and tempfiles =="
-  system "rm -f log/*"
-  system "rm -rf tmp/cache"
+  system! 'bin/rails log:clear tmp:clear'
 
   puts "\n== Restarting application server =="
-  system "touch tmp/restart.txt"
+  system! 'bin/rails restart'
 end
diff --git a/bin/update b/bin/update
new file mode 100755
index 00000000..a8e4462f
--- /dev/null
+++ b/bin/update
@@ -0,0 +1,29 @@
+#!/usr/bin/env ruby
+require 'pathname'
+require 'fileutils'
+include FileUtils
+
+# path to your application root.
+APP_ROOT = Pathname.new File.expand_path('../../', __FILE__)
+
+def system!(*args)
+  system(*args) || abort("\n== Command #{args} failed ==")
+end
+
+chdir APP_ROOT do
+  # This script is a way to update your development environment automatically.
+  # Add necessary update steps to this file.
+
+  puts '== Installing dependencies =='
+  system! 'gem install bundler --conservative'
+  system('bundle check') || system!('bundle install')
+
+  puts "\n== Updating database =="
+  system! 'bin/rails db:migrate'
+
+  puts "\n== Removing old logs and tempfiles =="
+  system! 'bin/rails log:clear tmp:clear'
+
+  puts "\n== Restarting application server =="
+  system! 'bin/rails restart'
+end
diff --git a/config/application.rb b/config/application.rb
index cd497243..68c8d943 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -1,4 +1,4 @@
-require File.expand_path('../boot', __FILE__)
+require_relative 'boot'
 
 require 'rails/all'
 
@@ -14,13 +14,6 @@ module Justask
     # Application configuration should go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded.
 
-    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
-    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
-    # config.time_zone = 'Central Time (US & Canada)'
-
-    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
-    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
-    # config.i18n.default_locale = :de
     config.autoload_paths += %W["#{config.root}/app/validators"]
 
     # Use Sidekiq for background jobs
@@ -30,14 +23,6 @@ module Justask
     config.i18n.fallbacks = true
     config.i18n.enforce_available_locales = false
 
-
-    # DEPRECATION WARNING: Currently, Active Record suppresses errors raised
-    # within `after_rollback`/`after_commit` callbacks and only print them to the logs.
-    # In the next version, these errors will no longer be suppressed.
-    # Instead, the errors will propagate normally just like in other Active Record callbacks.
-    # fix for this warning:
-    config.active_record.raise_in_transactional_callbacks = true
-
     config.after_initialize do
       Dir.glob Rails.root.join('config/late_initializers/*.rb') do |f|
         require f
diff --git a/config/boot.rb b/config/boot.rb
index 5e5f0c1f..30f5120d 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,4 +1,3 @@
-# Set up gems listed in the Gemfile.
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+require 'bundler/setup' # Set up gems listed in the Gemfile.
diff --git a/config/cable.yml b/config/cable.yml
new file mode 100644
index 00000000..0bbde6f7
--- /dev/null
+++ b/config/cable.yml
@@ -0,0 +1,9 @@
+development:
+  adapter: async
+
+test:
+  adapter: async
+
+production:
+  adapter: redis
+  url: redis://localhost:6379/1
diff --git a/config/deploy.rb b/config/deploy.rb
index f7c6ebd1..2cf3bb7b 100644
--- a/config/deploy.rb
+++ b/config/deploy.rb
@@ -1,5 +1,5 @@
 # config valid only for current version of Capistrano
-lock "3.8.0"
+lock "3.13.0"
 
 set :application, "retrospring"
 set :repo_url, "git@git.rrerr.net:nilsding/retrospring.git"
diff --git a/config/environment.rb b/config/environment.rb
index b90d71e9..80cc1632 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -1,5 +1,5 @@
 # Load the Rails application.
-require File.expand_path('../application', __FILE__)
+require_relative 'application'
 
 # Initialize the Rails application.
 start = Time.now
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 30738511..cd66aa46 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -9,9 +9,22 @@ Rails.application.configure do
   # Do not eager load code on boot.
   config.eager_load = false
 
-  # Show full error reports and disable caching.
-  config.consider_all_requests_local       = true
-  config.action_controller.perform_caching = false
+  # Show full error reports.
+  config.consider_all_requests_local = true
+
+  # Enable/disable caching. By default caching is disabled.
+  if Rails.root.join('tmp/caching-dev.txt').exist?
+    config.action_controller.perform_caching = true
+
+    config.cache_store = :memory_store
+    config.public_file_server.headers = {
+      'Cache-Control' => 'public, max-age=172800'
+    }
+  else
+    config.action_controller.perform_caching = false
+
+    config.cache_store = :null_store
+  end
 
   # Action Mailer Setup
   # if you want to test sending mails locally, uncomment the line below and comment the :sendmail line
@@ -25,10 +38,11 @@ Rails.application.configure do
     config.action_mailer.delivery_method = :sendmail
   end
 
-  config.action_mailer.perform_deliveries = true
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false
 
+  config.action_mailer.perform_caching = false
+
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
@@ -40,11 +54,13 @@ Rails.application.configure do
   # number of complex assets.
   config.assets.debug = true
 
-  # Adds additional error checking when serving assets at runtime.
-  # Checks for improperly declared sprockets dependencies.
-  # Raises helpful error messages.
-  config.assets.raise_runtime_errors = true
+  # Suppress logger output for asset requests.
+  config.assets.quiet = true
 
   # Raises error for missing translations
   # config.action_view.raise_on_missing_translations = true
+
+  # Use an evented file watcher to asynchronously detect changes in source code,
+  # routes, locales, etc. This feature depends on the listen gem.
+  # config.file_watcher = ActiveSupport::EventedFileUpdateChecker
 end
diff --git a/config/environments/production.rb b/config/environments/production.rb
index 1c5656b5..cbacd711 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -14,13 +14,9 @@ Rails.application.configure do
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
 
-  # Enable Rack::Cache to put a simple HTTP cache in front of your application
-  # Add `rack-cache` to your Gemfile before enabling this.
-  # For large-scale production use, consider using a caching reverse proxy like nginx, varnish or squid.
-  # config.action_dispatch.rack_cache = true
-
-  # Disable Rails's static asset server (Apache or nginx will already do this).
-  config.serve_static_files = false
+  # Disable serving static files from the `/public` folder by default since
+  # Apache or NGINX already handles this.
+  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
 
   # Compress JavaScripts and CSS.
   config.assets.js_compressor = :uglifier
@@ -29,36 +25,41 @@ Rails.application.configure do
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # Generate digests for assets URLs.
-  config.assets.digest = true
+  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
 
-  # `config.assets.precompile` has moved to config/initializers/assets.rb
+  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
+  # config.action_controller.asset_host = 'http://assets.example.com'
 
   # Specifies the header that your server uses for sending files.
-  # config.action_dispatch.x_sendfile_header = "X-Sendfile" # for apache
-  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for nginx
+  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
+  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
+
+  # Mount Action Cable outside main process or domain
+  # config.action_cable.mount_path = nil
+  # config.action_cable.url = 'wss://example.com/cable'
+  # config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]
 
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   # config.force_ssl = true
 
-  # Set to :debug to see everything in the log.
-  config.log_level = :info
+  # Use the lowest log level to ensure availability of diagnostic information
+  # when problems arise.
+  config.log_level = :debug
 
   # Prepend all log lines with the following tags.
-  # config.log_tags = [ :subdomain, :uuid ]
-
-  # Use a different logger for distributed setups.
-  # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
+  config.log_tags = [ :request_id ]
 
   # Use a different cache store in production.
   # config.cache_store = :mem_cache_store
 
-  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
-  # config.action_controller.asset_host = "http://assets.example.com"
+  # Use a real queuing backend for Active Job (and separate queues per environment)
+  # config.active_job.queue_adapter     = :resque
+  # config.active_job.queue_name_prefix = "justask_#{Rails.env}"
+  config.action_mailer.perform_caching = false
 
-  # Precompile additional assets.
-  # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
-  # config.assets.precompile += %w( search.js )
+  # Ignore bad email addresses and do not raise email delivery errors.
+  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
+  # config.action_mailer.raise_delivery_errors = false
 
   # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
   # the I18n.default_locale when a translation cannot be found).
@@ -67,19 +68,19 @@ Rails.application.configure do
   # Send deprecation notices to registered listeners.
   config.active_support.deprecation = :notify
 
-  config.action_mailer.delivery_method = :sendmail
-  # config.action_mailer.default_url_options = { host: 'retrospring.net' }
-  config.action_mailer.perform_deliveries = true
-  # Ignore bad email addresses and do not raise email delivery errors.
-  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
-  config.action_mailer.raise_delivery_errors = true
-
-  # Disable automatic flushing of the log to improve performance.
-  # config.autoflush_log = false
-
   # Use default logging formatter so that PID and timestamp are not suppressed.
   config.log_formatter = ::Logger::Formatter.new
 
+  # Use a different logger for distributed setups.
+  # require 'syslog/logger'
+  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
+
+  if ENV["RAILS_LOG_TO_STDOUT"].present?
+    logger           = ActiveSupport::Logger.new(STDOUT)
+    logger.formatter = config.log_formatter
+    config.logger = ActiveSupport::TaggedLogging.new(logger)
+  end
+
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
 end
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 0d6459df..30587ef6 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -12,9 +12,11 @@ Rails.application.configure do
   # preloads Rails for running tests, you may have to set it to true.
   config.eager_load = false
 
-  # Configure static asset server for tests with Cache-Control for performance.
-  config.serve_static_files   = true
-  config.static_cache_control = 'public, max-age=3600'
+  # Configure public file server for tests with Cache-Control for performance.
+  config.public_file_server.enabled = true
+  config.public_file_server.headers = {
+    'Cache-Control' => 'public, max-age=3600'
+  }
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
@@ -25,6 +27,7 @@ Rails.application.configure do
 
   # Disable request forgery protection in test environment.
   config.action_controller.allow_forgery_protection = false
+  config.action_mailer.perform_caching = false
 
   # Tell Action Mailer not to deliver emails to the real world.
   # The :test delivery method accumulates sent emails in the
diff --git a/config/initializers/application_controller_renderer.rb b/config/initializers/application_controller_renderer.rb
new file mode 100644
index 00000000..89d2efab
--- /dev/null
+++ b/config/initializers/application_controller_renderer.rb
@@ -0,0 +1,8 @@
+# Be sure to restart your server when you modify this file.
+
+# ActiveSupport::Reloader.to_prepare do
+#   ApplicationController.renderer.defaults.merge!(
+#     http_host: 'example.org',
+#     https: false
+#   )
+# end
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index 0c0205fe..e321065f 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -3,6 +3,9 @@
 # Version of your assets, change this if you want to expire all your assets.
 Rails.application.config.assets.version = '1.0'
 
+# Add additional assets to the asset load path
+# Rails.application.config.assets.paths << Emoji.images_path
+
 # Precompile additional assets.
 # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
 Rails.application.config.assets.precompile += %w( moderation.js )
diff --git a/config/initializers/cookies_serializer.rb b/config/initializers/cookies_serializer.rb
index 7a06a89f..5a6a32d3 100644
--- a/config/initializers/cookies_serializer.rb
+++ b/config/initializers/cookies_serializer.rb
@@ -1,3 +1,5 @@
 # Be sure to restart your server when you modify this file.
 
-Rails.application.config.action_dispatch.cookies_serializer = :json
\ No newline at end of file
+# Specify a serializer for the signed and encrypted cookie jars.
+# Valid options are :json, :marshal, and :hybrid.
+Rails.application.config.action_dispatch.cookies_serializer = :json
diff --git a/config/initializers/devise_async.rb b/config/initializers/devise_async.rb
index 05a1852c..8f24c4a8 100644
--- a/config/initializers/devise_async.rb
+++ b/config/initializers/devise_async.rb
@@ -1 +1 @@
-Devise::Async.backend = :sidekiq
+Devise::Async.enabled = true
diff --git a/config/initializers/haml.rb b/config/initializers/haml.rb
deleted file mode 100644
index 7e8ddb37..00000000
--- a/config/initializers/haml.rb
+++ /dev/null
@@ -1 +0,0 @@
-Haml::Template.options[:ugly] = true
diff --git a/config/initializers/new_framework_defaults.rb b/config/initializers/new_framework_defaults.rb
new file mode 100644
index 00000000..9bbfaab6
--- /dev/null
+++ b/config/initializers/new_framework_defaults.rb
@@ -0,0 +1,20 @@
+# Be sure to restart your server when you modify this file.
+#
+# This file contains migration options to ease your Rails 5.0 upgrade.
+#
+# Once upgraded flip defaults one by one to migrate to the new default.
+#
+# Read the Guide for Upgrading Ruby on Rails for more info on each option.
+
+# Enable per-form CSRF tokens. Previous versions had false.
+Rails.application.config.action_controller.per_form_csrf_tokens = false
+
+# Enable origin-checking CSRF mitigation. Previous versions had false.
+Rails.application.config.action_controller.forgery_protection_origin_check = false
+
+# Make Ruby 2.4 preserve the timezone of the receiver when calling `to_time`.
+# Previous versions had false.
+ActiveSupport.to_time_preserves_timezone = false
+
+# Require `belongs_to` associations by default. Previous versions had false.
+Rails.application.config.active_record.belongs_to_required_by_default = true# false
diff --git a/config/initializers/wrap_parameters.rb b/config/initializers/wrap_parameters.rb
index 33725e95..bbfc3961 100644
--- a/config/initializers/wrap_parameters.rb
+++ b/config/initializers/wrap_parameters.rb
@@ -5,10 +5,10 @@
 
 # Enable parameter wrapping for JSON. You can disable this by setting :format to an empty array.
 ActiveSupport.on_load(:action_controller) do
-  wrap_parameters format: [:json] if respond_to?(:wrap_parameters)
+  wrap_parameters format: [:json]
 end
 
 # To enable root element in JSON for ActiveRecord objects.
 # ActiveSupport.on_load(:active_record) do
-#  self.include_root_in_json = true
+#   self.include_root_in_json = true
 # end
diff --git a/config/puma.rb b/config/puma.rb
new file mode 100644
index 00000000..c7f311f8
--- /dev/null
+++ b/config/puma.rb
@@ -0,0 +1,47 @@
+# Puma can serve each request in a thread from an internal thread pool.
+# The `threads` method setting takes two numbers a minimum and maximum.
+# Any libraries that use thread pools should be configured to match
+# the maximum value specified for Puma. Default is set to 5 threads for minimum
+# and maximum, this matches the default thread size of Active Record.
+#
+threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }.to_i
+threads threads_count, threads_count
+
+# Specifies the `port` that Puma will listen on to receive requests, default is 3000.
+#
+port        ENV.fetch("PORT") { 3000 }
+
+# Specifies the `environment` that Puma will run in.
+#
+environment ENV.fetch("RAILS_ENV") { "development" }
+
+# Specifies the number of `workers` to boot in clustered mode.
+# Workers are forked webserver processes. If using threads and workers together
+# the concurrency of the application would be max `threads` * `workers`.
+# Workers do not work on JRuby or Windows (both of which do not support
+# processes).
+#
+# workers ENV.fetch("WEB_CONCURRENCY") { 2 }
+
+# Use the `preload_app!` method when specifying a `workers` number.
+# This directive tells Puma to first boot the application and load code
+# before forking the application. This takes advantage of Copy On Write
+# process behavior so workers use less memory. If you use this option
+# you need to make sure to reconnect any threads in the `on_worker_boot`
+# block.
+#
+# preload_app!
+
+# The code in the `on_worker_boot` will be called if you are using
+# clustered mode by specifying a number of `workers`. After each worker
+# process is booted this block will be run, if you are using `preload_app!`
+# option you will want to use this block to reconnect to any threads
+# or connections that may have been created at application boot, Ruby
+# cannot share connections between processes.
+#
+# on_worker_boot do
+#   ActiveRecord::Base.establish_connection if defined?(ActiveRecord)
+# end
+
+# Allow puma to be restarted by `rails restart` command.
+plugin :tmp_restart
diff --git a/config/secrets.yml b/config/secrets.yml
index 2e5654bd..064543d6 100644
--- a/config/secrets.yml
+++ b/config/secrets.yml
@@ -5,7 +5,7 @@
 
 # Make sure the secret is at least 30 characters and all random,
 # no regular words or you'll be exposed to dictionary attacks.
-# You can use `rake secret` to generate a secure secret key.
+# You can use `rails secret` to generate a secure secret key.
 
 # Make sure the secrets in this file are kept private
 # if you're sharing your code publicly.
diff --git a/config/sidekiq.yml b/config/sidekiq.yml
index f504264e..6da98de3 100644
--- a/config/sidekiq.yml
+++ b/config/sidekiq.yml
@@ -8,9 +8,8 @@ production:
 :queues:
   - share
   - paperclip
-  - mailer
+  - mailers
   - deletion
-  - rollbar
   - question
   - export
 
diff --git a/config/spring.rb b/config/spring.rb
new file mode 100644
index 00000000..c9119b40
--- /dev/null
+++ b/config/spring.rb
@@ -0,0 +1,6 @@
+%w(
+  .ruby-version
+  .rbenv-vars
+  tmp/restart.txt
+  tmp/caching-dev.txt
+).each { |path| Spring.watch(path) }
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 00000000..90553f7d
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,29 @@
+version: "3.7"
+
+services:
+  web:
+    build:       
+      context: .      
+      dockerfile: .docker/ruby/Dockerfile
+    command:
+      ruby bin/rails server --port 3000 --binding 0.0.0.0
+    links:
+      - postgres
+      - redis
+    volumes:
+      - ./:/app
+    ports:
+      - 3000:3000
+
+  redis:
+    image: redis:3.2.11-alpine
+    ports: 
+      - 6379:6379
+
+  postgres:
+    image: postgres:10.12
+    ports:
+      - 5432:5432
+    environment:
+      POSTGRES_PASSWORD: justask
+      POSTGRES_DB: justask_development
\ No newline at end of file