Add UserCredential to the resolve function in auth.signInWithEmailAndPassword so that it is consistent with the web api.
Add UserCredential to the resolve function in auth.signInWithEmailAndPassword so that it is consistent with the web api.

EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase