added sanitize gem

Gemfile

@@ -40,6 +40,7 @@ gem 'sinatra', require: false
 
 gem 'questiongenerator', git: 'https://github.com/justask/questiongenerator.git'
 
+gem 'sanitize'
 gem 'redcarpet'
 
 # OmniAuth and providers

Gemfile.lock

@@ -77,6 +77,7 @@ GEM
     coffee-script-source (1.8.0)
     colorize (0.7.5)
     connection_pool (2.1.0)
+    crass (1.0.1)
     daemons (1.1.9)
     database_cleaner (1.3.0)
     devise (3.4.1)
@@ -152,6 +153,8 @@ GEM
     net-ssh (2.9.1)
     nokogiri (1.6.5)
       mini_portile (~> 0.6.0)
+    nokogumbo (1.2.0)
+      nokogiri
     nprogress-rails (0.1.6.3)
     oauth (0.4.7)
     omniauth (1.2.2)
@@ -239,6 +242,10 @@ GEM
     rspec-support (3.0.4)
     ruby-progressbar (1.7.0)
     safe_yaml (1.0.4)
+    sanitize (3.1.0)
+      crass (~> 1.0.1)
+      nokogiri (>= 1.4.4)
+      nokogumbo (= 1.2.0)
     sass (3.2.19)
     sass-rails (4.0.5)
       railties (>= 4.0.0, < 5.0)
@@ -357,6 +364,7 @@ DEPENDENCIES
   redis
   rspec-rails (~> 3.0.0)
   ruby-progressbar
+  sanitize
   sass-rails (~> 4.0.3)
   sdoc (~> 0.4.1)
   sidekiq