Change debug option to speed up css compilation.

config/environments/development.rb

@@ -48,7 +48,7 @@ Rails.application.configure do
   # Debug mode disables concatenation and preprocessing of assets.
   # This option may cause significant delays in view rendering with a large
   # number of complex assets.
-  config.assets.debug = true
+  config.assets.debug = false
 
   # Suppress logger output for asset requests.
   config.assets.quiet = true