Show the author's name on each commit

There was already code to display this, but it was either buggy or relied on an outdated API response format from GitHub.

There's now a smidgen of padding to the names to separate them from the commit messages themselves.

![Commit log with author names](https://cloud.githubusercontent.com/assets/32775/3384992/3df2bb3c-fc64-11e3-9e2f-8e223b0b5d1f.png)