title: setup pre-commit hook jshint
body: <p>I recently started a <a href="https://github.com/scaljeri/sway">project on github</a>.
  I've managed to setup automatic testing after each commit using Travis. But now I would like to setup a pre-commit hook with jshint too. So if jshint reports errors, the commit should fail. But is this possible, and if so, how to do this ?</p>