Integrated optional junit xml output

Adds 3 new configurations to CLI and guard config:
* junit - set to true to save output to xml files (false by default)
* junit_consolidate - rolls nested describes up into their parent describe blocks (true by default)
* junit_save_path - optional path to save the xml files to

Uses the junit reporter created by larrymyers from github/com/larrymyers/jasmine-reporters