Clean up all lint errors and some lint warnings.
Update travis.
Bump down play servers and sdk.
Add a ToastReceiver on the UI-thread that listens for toast-able
messages from the back end.

Add robolectric to testing suite (for android-specific code).
Upgrade to gradle 2.1.
Make travis only run tests, not package.
Merge pull request #71 from trhodeos/tr.fix-toast

Add a ToastReceiver on the UI-thread that listens for toast-able
Merge branch 'dev' into lintify
Merge pull request #80 from nightscout/lintify

Lintify
Merge branch 'dev' into wip/data-opt-in.