Ignore generated service plist

Keep contributors from accidentally committing their local version.
Add grunt, release task.

We're using grunt-semantic-release FTW.

Stub out a "test" grunt task — All it's doing for now is linting the Gruntfile, but that will change. Soon, it will lint *all* the files!
Add us some Travis.
Merge pull request #34 from bobthecow/feature/semantic-releases

Add semantic release support.