Update json dependency to version 1.6.4
Update json dependency to version 1.6.4

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