func createNewUser(email: String, password: String) {
    Auth.auth().createUser(withEmail: email, password: password) { user, error in
        if error == nil && user != nil { //user create works
            print(user, "<-- User Created (user)")
        } else { //user not create
            print("Error creating user: (error!.localizedDescription)")
        }

        //database integration
        let ref = Database.database().reference()
        let usersRef = ref.child("users2")

        let uid = user?.user.uid
        print(email, "<-- email")

        print(uid, "<-- this is uid")
        let newUserRef = usersRef.child(uid!)//This fails because UID is nil
        newUserRef.setValue(["email": self.emailTextField.text!, "password": self.passwordTextField.text!, "fullName": self.fullNameTextField.text!, "username": self.usernameTextField.text!])

        print(email, "<--- this is emaiL??")

    } //end of create user

}

guard let authResult = authResult, error == nil else {
   return // an error!
}

if let user = authResult.user {
    let uid = user.uid {
        print("uid is (uid)")
    }
    if let email = user.email {
        print("email is (email)")
    }
}