Update rack to version 1.6.0
Update rack to version 1.6.0

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