Merge pull request #663 from node-apn/prep-3.0-II

Prep for release

Update changelog for 2.1.4

Update version to 2.1.2

2.1.0

* JSON Web Token support (#401)
* Add threadId property for notifications
* Fix a leak caused when an error is emitted from the endpoint manager

v2.0.0

* HTTP/2 Provider API (#277)
* `apn.Connection` has been renamed to `apn.Provider`
* `apn.Feedback` has been removed
* `apn.Device` has been removed - all tokens are now hex-encoded strings
* `apn.token` is provided to validate tokens and convert from `Buffer` if
  necessary
* Notifications are now required to have an associated `topic`
* `pushNotification(notification, tokens)` is now simply, `send(notification, recipients)`
* `send` returns a promise which will be fulfilled when all notifications have
  been sent (#362)
* Reliable Delivery (#168)
* Ability to mock `apn.Provider` behaviour
* Notification can be created in a "finished" state (#240)