PlumLabs/m — pull request #12 by saulcoria (2014-04-23 22:49:57+00:00)
Title: Sc/create discount

Here is created ```Discount``` model and integrated it into ActiveAdmin. Here is a [video]
(https://s3.amazonaws.com/uploads.hipchat.com/89325/648614/FjWapYT15D8eulD/discount.ogv) showing it.