Fixed app.json file.
Fixed app.json file.

TwilioDevEd/clicktocall-node,jschairb/ctc-poc,demandforce/clicktocall-node,demandforce/clicktocall-node,burnoutberni/clickToCallYourMEP,jschairb/ctc-poc,TwilioDevEd/clicktocall-node,TwilioDevEd/clicktocall-node,burnoutberni/clickToCallYourMEP,jschairb/ctc-poc