Update instructions for Ember CLI.
Update instructions for Ember CLI.

* Add instructions for adding to Ember CLI.
* Remove reference to EAK (it will be deprecated shortly).

IsaiahJTurner/emberfire,FirebaseExtended/emberfire,gerrymclarnon/emberFire,rtablada/emberfire,leifcr/emberfire,IsaiahJTurner/emberfire,FirebaseExtended/emberfire,19degrees/emberfire,FirebaseExtended/emberfire,gerrymclarnon/emberFire,MattMSumner/emberfire,19degrees/emberfire,rtablada/emberfire,leifcr/emberfire,FirebaseExtended/emberfire,MattMSumner/emberfire