A sample push API consumer for the new foursquare push API.

Has a very simple endpoint for doing OAuth, and a /checkin handler that receives a POST with checkin and user JSON. The POST is expected to have a "checkin" parameter containing a JSON checkin object, with "user" and "venue" json inside it. Those formats are described in more depth at http://developer.foursquare.com/docs/responses/checkin.html.