index.html references non existent js files due to a path bug

404 errors in the default index.html due to two script files missing:

```
  <script src="js/phaser.js"></script>
  <script src="js/game.js"></script>
```

Both these need to be prefixed with the 'dist/' directory.

```
  <script src="dist/js/phaser.js"></script>
  <script src="dist/js/game.js"></script>
```

The default Phaser output then shows up with the Yeoman animation.
