Added ember-firebase to the README
Added ember-firebase to the README

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