Show email used to author commit

Show email used to author commit as part of the "and criteria":

![show-email](https://cloud.githubusercontent.com/assets/65057/3351995/bad11c56-fa2b-11e3-92d4-e0cba421f454.png)

Enabled by https://github.com/jdennes/contribution-checker/pull/4

Branch deployed: http://contribution-checker.herokuapp.com/

There are also some other markup and style changes included to simplify and improve the results tables (particularly when viewed on a mobile device).