added line-height to footer ul elements to make them of same height

Before:
![before](https://cloud.githubusercontent.com/assets/1220480/5530085/051b0366-8a42-11e4-8979-34592e91e2e0.png)

After:
![after](https://cloud.githubusercontent.com/assets/1220480/5530088/08db2b0c-8a42-11e4-8b53-49d207c41ad1.png)

Check the right side Sponsorship links :+1: