configurei meus arquivos conforme as aulas porem o token não é gerado

package br.com.vinipaulino.mobile.agenda.firebase;

import android.util.Log;

import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.FirebaseInstanceIdService;

import br.com.vinipaulino.mobile.agenda.retrofit.RetrofitInicializador;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;

/**
 * Created by vinyp on 27/02/2018.
 */

public class AgendaInstanceIDService extends FirebaseInstanceIdService {
    @Override
    public void onTokenRefresh() {
        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
        Log.d("token firebase", "Refreshed token: " + refreshedToken);

        enviaTokenParaServidor(refreshedToken);
    }

    private void enviaTokenParaServidor(final String token) {
        Call<Void> call = new RetrofitInicializador().getDispositivoService().enviaToken(token);

        call.enqueue(new Callback<Void>() {
            @Override
            public void onResponse(Call<Void> call, Response<Void> response) {
                Log.i("token enviado", token);
            }

            @Override
            public void onFailure(Call<Void> call, Throwable t) {
                Log.e("tokem não enviado", String.valueOf(t));
            }
        });
    }
}

Android Manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="br.com.vinipaulino.mobile.agenda">

    <uses-permission android:name="android.permission.CALL_PHONE" />
    <uses-permission android:name="android.permission.RECEIVE_SMS" />
    <uses-permission android:name="android.permission.INTERNET" />

    <!--
         The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but you must specify either coarse or fine
         location permissions for the 'MyLocation' functionality. 
    -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".activity.ListaAlunosActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".activity.FormularioActivity" />

        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="${applicationId}.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths" />
        </provider>

        <receiver
            android:name=".receiver.SmsReceiver"
            android:enabled="true">
            <intent-filter>
                <action android:name="android.provider.Telephony.SMS_RECEIVED" />
            </intent-filter>
        </receiver>

        <activity android:name=".activity.ProvasActivity" />
        <!--
             The API key for Google Maps-based APIs is defined as a string resource.
             (See the file "res/values/google_maps_api.xml").
             Note that the API key is linked to the encryption key used to sign the APK.
             You need a different API key for each encryption key, including the release key that is used to
             sign the APK for publishing.
             You can define the keys for the debug and release targets in src/debug/ and src/release/. 
        -->
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />

        <service
            android:name=".firebase.AgendaInstanceIDService">
            <intent-filter>
                <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
            </intent-filter>
        </service>
    </application>

</manifest>