Merge pull request #681 from Neilos/fix-monetized-attributes-class-discrepancy

Fix monetized_attributes class discrepancy

Author: semmons99

lib/money-rails/active_record/monetizable.rb

@@ -10,7 +10,7 @@ class ReadOnlyCurrencyException < MoneyRails::Error; end
 
       module ClassMethods
         def monetized_attributes
-          monetized_attributes = @monetized_attributes || {}
+          monetized_attributes = @monetized_attributes || {}.with_indifferent_access
 
           if superclass.respond_to?(:monetized_attributes)
             monetized_attributes.merge(superclass.monetized_attributes)