Updated to iOS SDK 2.2.3 and Android SDK 1.4, cleaned up repo

* References to teamToken have been replaced with appToken
* setDeviceIdentifier() and setDeviceIdentifierUUID() JS methods still
exist, but they print out a console warning about being deprecated and
will fire the success callback immediately without executing native code
Bumping version to 2.1.0

The switch from team token to app token is a breaking change, and two
methods have been marked as deprecated