Version 2.0.0 supports SwiftfulAuthenticating (https://github.com/SwiftfulThinking/SwiftfulAuthenticating).
SwiftfulFirebaseAuth, used in version 1.0.0 is now deprecated.
SwiftfulAuthenticating decouples AuthManager from Firebase for use with other dependencies and has improved testing/mocking/preview flexibility.
SwiftfulAuthenticating also drops sign in with phone support (tbd).