add description how to use local testing for mails

Gemfile.lock

@@ -242,6 +242,10 @@ GEM
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
     kgio (2.9.3)
+    launchy (2.4.3)
+      addressable (~> 2.3)
+    letter_opener (1.4.1)
+      launchy (~> 2.2)
     loofah (2.0.1)
       nokogiri (>= 1.5.9)
     mail (2.6.3)
@@ -503,6 +507,7 @@ DEPENDENCIES
   jbuilder (~> 2.2.4)
   jquery-rails
   jquery-turbolinks
+  letter_opener
   momentjs-rails (>= 2.9.0)
   mysql2
   nprogress-rails

config/environments/development.rb

@@ -13,8 +13,11 @@ Rails.application.configure do
   config.consider_all_requests_local       = true
   config.action_controller.perform_caching = false
 
+  # Action Mailer Setup
+  # if you want to test sending mails locally, uncomment the line below and comment the :sendmail line
+  # config.action_mailer.delivery_method = :letter_opener
   config.action_mailer.delivery_method = :sendmail
-  config.action_mailer.default_url_options = { host: 'justask.local' }
+  config.action_mailer.default_url_options = { host: 'localhost:3000' }
   config.action_mailer.perform_deliveries = true
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false