Ensure importer accepts context reference

Author: josh

lib/sass/rails/importer.rb

@@ -1,3 +1,4 @@
+require 'sass'
 require 'sprockets/sass_importer'
 
 module Sprockets
@@ -7,6 +8,11 @@ class SassImporter < Sass::Importers::Filesystem
     attr_reader :context
     private :context
 
+    def initialize(context, root)
+      @context = context
+      super root.to_s
+    end
+
     def extensions
       {
         'css'          => :scss,