sanction 0.3.1 (4-8-2013)
=========================
* Added refresh_token, defaulting to None instead of dynamically adding it
  to the client instance

sanction 0.3 (2-21-2013)
========================
* Python 3+ support added
* Updated request to support a full range of HTTP methods (was previously POST
  and GET
* Added support for multiple token transport types: HTTP headers, GET params
  or custom callable
* Added exclude param to request_token in order to prevent certain fields from
  token request
* Removed query param from request. These should now be added to the base url.

sanction 0.1.4 (9-14-2012)
==========================
* Added support for refresh_token
* Removed check for endpoint errors in request_token. Client code should 
  deal with that before calling request_token.
