Move all firbase dependencies from actions layer to firebaseService layer (#13)

app/services/notifications/INotificationService.ts

@@ -1,15 +1,16 @@
 import { User } from 'domain/users'
 
-
-
+import { Notification } from 'domain/notifications'
 
 /**
  * Notification service interface
- * 
+ *
  * @export
  * @interface INotificationService
  */
 export interface INotificationService {
-
-
-}
+  addNotification: (notification: Notification) => Promise<void>
+  getNotifications: (userId: string) => Promise<{[notifyId: string]: Notification}>
+  deleteNotification: (notificationId: string, userId: string) => Promise<void>
+  setSeenNotification: (notificationId: string, userId: string, notification: Notification) => Promise<void>
+}