Stick with 1.8 syntax

Author: josh

lib/sprockets/railtie.rb

@@ -40,7 +40,7 @@ def assets
   class Engine < Railtie
     # Skip defining append_assets_path on Rails <= 4.2
     unless initializers.find { |init| init.name == :append_assets_path }
-      initializer :append_assets_path, group: :all do |app|
+      initializer :append_assets_path, :group => :all do |app|
         app.config.assets.paths.unshift(*paths["vendor/assets"].existent_directories)
         app.config.assets.paths.unshift(*paths["lib/assets"].existent_directories)
         app.config.assets.paths.unshift(*paths["app/assets"].existent_directories)