add rack-cors; fix #531

Gemfile

@@ -18,6 +18,7 @@ gem 'kaminari' # pagination
 gem 'uservoice-ruby'
 gem 'dotenv'
 gem 'snorlax'
+gem 'rack-cors'
 gem 'httparty'
 gem 'active_model_serializers', '~> 0.8.1'
 gem 'delayed_job', '~> 4.0.2'

Gemfile.lock

@@ -160,6 +160,7 @@ GEM
     quiet_assets (1.1.0)
       railties (>= 3.1, < 5.0)
     rack (1.6.4)
+    rack-cors (0.4.0)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.2.4)
@@ -286,6 +287,7 @@ DEPENDENCIES
   pundit
   pundit_extra
   quiet_assets
+  rack-cors
   rails (= 4.2.4)
   rails3-jquery-autocomplete
   rails_12factor

config/initializers/cors.rb

@@ -0,0 +1,8 @@
+Rails.application.config.middleware.insert_before 0, Rack::Cors do
+  allow do
+    origins '*'
+    resource '*',
+      headers: :any,
+      methods: [:get, :post, :put, :delete, :options, :head]
+  end
+end