Gemfile in sidekiq_send_mail-0.1.1 vs Gemfile in sidekiq_send_mail-0.1.2

@@ -1,3 +1,16 @@
 source 'http://rubygems.org'
 
 gemspec
+
+rails_version = ENV['RAILS_VERSION'] || 'default'
+
+rails = case rails_version
+          when 'master'
+            {github: 'rails/actionmailer'}
+          when 'default'
+            '>= 3.2'
+          else
+            "~> #{rails_version}"
+        end
+
+gem 'actionmailer', rails
\ No newline at end of file