Fixes broken game example

sky/sdk/example/game/main.dart

 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/widget.dart';
+import 'package:sky/mojo/net/fetch.dart';
 
 import 'lib/game_demo.dart';
 import 'lib/sprites.dart';
 
 void main() {
   // Load images
   new ImageMap([
       "res/nebula.png",
       "res/sprites.png",
     ],
@@ skipping 32 matching lines @@
 //        ]),
 //        right:0.0,
 //        top: 20.0
 //      )
     ]);
   }
 }
 
 ImageMap _loader;
 SpriteSheet _spriteSheet;