Remove excess padding from the bottom of a speaker

This had the effect of having an odd block of whitespace at the top of each speaker (except the first) when in a list, especially when coupled with the horizontal rule that we use as a separator.
The same change has also been applied to the sessions page.
Merge pull request #97 from adrianbanks/remove-excess-padding

Remove excess padding from the bottom of a speaker.

This had the effect of having an odd block of whitespace at the top of each speaker (except the first) when in a list, especially when coupled with the horizontal rule that we use as a separator.