Merge pull request #131 from mozilla-services/master

Updating dev from Stage/master changes.
Merge branch 'dev' of github.com:mozilla-services/FindMyDevice into dev
Add stop tracking when Web UI shuts down.

* Sends a track duration 0 to the device when display disconnects.
Added push for stop tracking command
Merge branch 'dev'
Merge branch 'master' of github.com:mozilla-services/FindMyDevice