replaced DS promise with RSVP promise in sortedOfferingsByDate.
replaced DS promise with RSVP promise in sortedOfferingsByDate.

djvoa12/frontend,dartajax/frontend,gabycampagna/frontend,ilios/frontend,gboushey/frontend,gboushey/frontend,thecoolestguy/frontend,dartajax/frontend,gabycampagna/frontend,jrjohnson/frontend,ilios/frontend,jrjohnson/frontend,djvoa12/frontend,thecoolestguy/frontend