Diplay the number of unread notifications / conversations

lib/models/count_unread_notifications.dart

@@ -0,0 +1,14 @@
+/// Count the number of unread notifications
+///
+/// @author Pierre Hubert
+
+class CountUnreadNotifications {
+  final int notifications;
+  final int conversations;
+
+  CountUnreadNotifications({
+    this.notifications,
+    this.conversations,
+  })  : assert(notifications != null),
+        assert(conversations != null);
+}