clean up

lib/data/services/messaging_service.dart

@@ -0,0 +1,9 @@
+typedef OnNotify(Map<String, dynamic> message);
+typedef OnSetupComplete(String token);
+
+abstract class MessagingService {
+  void init(OnNotify onMessage,
+      {OnNotify onLaunch, OnNotify onResume, OnSetupComplete onSetupComplete});
+  Future<void> subscribe(String topic);
+  Future<void> unsubscribe(String topic);
+}