Be more specific with required file

EiNSTeiN- · web-flow · commit 0671eb5e9121 · 2016-11-09T12:37:24.000-05:00
This fixes a problem with being unable to load `ActionView::Helpers::AssetUrlHelper` from L7 in some situations
diff --git a/lib/sprockets/rails/context.rb b/lib/sprockets/rails/context.rb
@@ -1,4 +1,4 @@
-require 'action_view'
+require 'action_view/helpers'
 require 'sprockets'
 
 module Sprockets
