List

Added ability to list tests, sites, and runs. Includes table_print gem dependency. 
![screenshot from 2014-12-21 13 00 06](https://cloud.githubusercontent.com/assets/914030/5519290/a615edf8-8911-11e4-8dce-93649aa4cdcc.png)

Note: this merge and the test merge (for launching runs with specific test ids and aborting specific runs) require special merging as lines 14 and 15 of lib/rainforest/cli/options.rb conflict.