Remove unneeded lines from travis.yml, fix cache.
Remove unneeded lines from travis.yml, fix cache.

TwilioDevEd/clicktocall-node,jschairb/ctc-poc,TwilioDevEd/clicktocall-node,TwilioDevEd/clicktocall-node,jschairb/ctc-poc,jschairb/ctc-poc