clean up buttons in footer of Account Settings page

# mobile width
![settings-mobile](https://cloud.githubusercontent.com/assets/203725/5040402/0baa8074-6b63-11e4-8189-89d1eb00b8e5.png)

# desktop width
![settings-desktop](https://cloud.githubusercontent.com/assets/203725/5040403/0baa8952-6b63-11e4-9de1-f6729a3e3bc9.png)

this makes the box-shadow be contained by the box frame, meaning when you say `margin-bottom: 10px` it doesn't look like `8px`.