add shimmer effect

example/lib/main.dart

@@ -21,7 +21,7 @@ void main() async {
     logLevel: Level.INFO,
     showLocalNotification:
         (!kIsWeb && Platform.isAndroid) ? showLocalNotification : null,
-    persistenceEnabled: true,
+    persistenceEnabled: false,
   );
 
   if (userId != null) {

example/pubspec.yaml

@@ -1,6 +1,6 @@
 name: example
 description: A new Flutter project.
-version: 1.0.59+61
+version: 1.0.60+62
 
 environment:
   sdk: ">=2.2.2 <3.0.0"