updated to Rails 4.2

config/environments/development.rb

@@ -13,8 +13,6 @@ Rails.application.configure do
   config.consider_all_requests_local       = true
   config.action_controller.perform_caching = false
 
-  config.action_mailer.perform_deliveries = true
-
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false
 
@@ -24,6 +22,15 @@ Rails.application.configure do
   # Raise an error on page load if there are pending migrations.
   config.active_record.migration_error = :page_load
 
+  # 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
+
+  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
+  # yet still be able to expire them through the digest params.
+  config.assets.digest = true
+
   # Adds additional error checking when serving assets at runtime.
   # Checks for improperly declared sprockets dependencies.
   # Raises helpful error messages.