recurly/recurly-client-ruby — pull request #140 by cbarton (2014-05-20 18:48:22+00:00)
Title: Add subscription change preview endpoint

This adds support for Subscription Change Preview http://docs.recurly.com/api/subscriptions#sub-change-preview.

Remember that previews and saving is mutually exclusive, so you cannot do a call chain like:

`subscription.preview.save`

And expect it to save the subscription.