spree/spree — pull request #4081 by peterberkenbosch (2013-12-09 13:32:25+00:00)
Title: make sure we search for a downcase coupon code

since that's what the [order is sending](https://github.com/spree/spree/blob/master/core/app/models/spree/order.rb#L449).

When you add a coupon code in all capitals in the backend, the coupon code will not be found. This fixes that.

part of #3567