Redesign status page

Redesigned status page based on https://github.com/cachethq/Cachet/issues/93.

Features:
- Font Open Sans.
- Timeline design.
- Changed some colours.
- Responsive.

Let me know what you think!

![status-screen](https://cloud.githubusercontent.com/assets/1803556/5563172/de08cabc-8e22-11e4-9126-92fbfacb91a3.png)