style(app): indent the generated `app.js` in a less off-putting manner.

Old: 
![screen shot 2014-02-28 at 9 37 28 am](https://f.cloud.github.com/assets/723048/2294712/e0248bdc-a085-11e3-9397-d5ff8b9668f5.png)

New:
![screen shot 2014-02-28 at 9 33 28 am](https://f.cloud.github.com/assets/723048/2294715/e426d38e-a085-11e3-82a8-9548c6ef5643.png)