Add space above footer

Adds a margin above the footer so that the page contents doesn't crash into it :)

Before:
![screen shot 2014-09-26 at 3 35 35 pm](https://cloud.githubusercontent.com/assets/1239550/4416322/5590b216-453f-11e4-9902-61b612350e77.png)

After:
![screen shot 2014-09-26 at 3 35 52 pm](https://cloud.githubusercontent.com/assets/1239550/4416323/5590acc6-453f-11e4-8a58-188cf602ca8d.png)


Closes #505