Adds Council logo to headers

![screen shot 2014-12-29 at 12 14 30](https://cloud.githubusercontent.com/assets/4236592/5568491/8fde65e4-8f54-11e4-8f3d-a6171740e0b4.png)
![screen shot 2014-12-29 at 12 14 55](https://cloud.githubusercontent.com/assets/4236592/5568492/923f6ef0-8f54-11e4-8381-b97c0be678ea.png)

I believe it's better to use the rails helpers here.