use new hash syntax

config/application.rb

@@ -70,10 +70,10 @@ module Gitlab
     config.middleware.use Rack::Cors do
       allow do
         origins '*'
-        resource '/api/*', 
+        resource '/api/*',
-          :headers => :any,
+          headers: :any,
-          :methods => [:get, :post, :options, :put, :delete],
+          methods: [:get, :post, :options, :put, :delete],
-          :expose => ['Link']
+          expose: ['Link']
       end
     end