Description: Require needed activesupport hash
 This require is necessary to use symbolize_keys method
Author: Lucas Kanashiro <kanashiro.duarte@gmail.com>
Last-Updated: 2016-03-14

--- a/lib/grape_entity/options.rb
+++ b/lib/grape_entity/options.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/hash'
+
 module Grape
   class Entity
     class Options