add just a little bit of padding to schedule slot on small form factor

Each of the schedule-slot could use a little bit of padding on the left and right so the speaker photo isn't right up to the border.

Before:
![before](https://cloud.githubusercontent.com/assets/253647/2956923/ec117bf2-da97-11e3-84dc-40780e6498cb.png)

After:
![after](https://cloud.githubusercontent.com/assets/253647/2956924/ee1963a6-da97-11e3-8f14-ab5bb92bb267.png)