Add unit testing

**The Issue**
Currently, code does not use unit testing. Unit testing allows for automated testing of functionality.

**Justification for this PR:**
http://stackoverflow.com/a/67500

**PR Breakdown**
* Add JUnit
* Add some simple tests for TimeUtil & StringUtil classes
* Fix a bug identified by unit test failing

**Note: while the commit shows "Add channel stats command", you'll still need to pull #6 because these PRs are separate**