add facebook link

![screen shot 2014-11-09 at 9 44 31 am](https://cloud.githubusercontent.com/assets/751779/4967838/61f5ed5e-6827-11e4-8fb9-1debbc46649f.png)
![screen shot 2014-11-09 at 9 44 51 am](https://cloud.githubusercontent.com/assets/751779/4967837/61e8daf6-6827-11e4-8352-ed23eb9bbc92.png)