gocardless/gocardless-ruby — pull request #20 by changs (2012-08-27 08:12:26+00:00)
Title: Add cancel! method to GoCardless::PreAuthorization 

Hi. I've added a method to cancel a pre_authorization, so now the gem should work as described in documentation.

```ruby
pre_auth = GoCardless::PreAuthorization.find("0540QD22SKND")
pre-auth.cancel!
```