Application posts when user is near their own registered Tessel

- TesselCheckinRepository posts to the server
- TesselRegistrationRepository saves the uuid that it gets back from the server, manages the list of knownTesselRegions (currently just the one that was registered by this user)
Fixed bug in which Checkins were posted to the wrong repository; Removed spec from app target

- Also added logging on checkin success/failure
Workaround for the fact that locationManager:didEnterRegion doesn't get called, but locationManager:didDetermineState:forRegion does get called