(refactor) Add styling for customer's and restaurant's sign-up pages

![screen shot 2014-09-05 at 9 06 39 am](https://cloud.githubusercontent.com/assets/6935952/4167874/abea11b8-3516-11e4-9d4a-3bfd083dd1f9.png)

![screen shot 2014-09-05 at 9 06 52 am](https://cloud.githubusercontent.com/assets/6935952/4167876/adbd366e-3516-11e4-8453-642525eaf962.png)