Update mocha dependency to version 0.12.3
Update mocha dependency to version 0.12.3

jasnow/follow-all,BryanH/follow-all,codeforamerica/follow-all,jasnow/follow-all,codeforamerica/follow-all,BryanH/follow-all,codeforamerica/follow-all,jasnow/follow-all,BryanH/follow-all