public async Task Login(string email, string senha)
        {
            Settings.UserToken = await firebaseAuthenticator.LoginWithEmailPassword(email, senha);

            Settings.UserKey = await firebaseHelper.GetUserKey(email);

            var pessoa = await firebaseHelper.GetPerson(email);

            Settings.UserName  = pessoa.NOME;
            Settings.UserEmail = pessoa.EMAIL;
            Settings.UserType  = pessoa.TIPO;

            MessagingCenter.Send(EventArgs.Empty, "GoToLogin");
        }