Added title (#614)

animations/lib/src/basics/03_animation_controller.dart

@@ -53,7 +53,9 @@ class _AnimationControllerDemoState extends State<AnimationControllerDemo>
     // when building child widgets. You can also check the status to see if the animation
     // has completed.
     return Scaffold(
-      appBar: AppBar(),
+      appBar: AppBar(
+        title: Text('Animation Controller'),
+      ),
       body: Center(
         child: Column(
           mainAxisSize: MainAxisSize.min,