Google Code-in

Add an automatic jslint check to the travis-ci build of django-netjsongraph which ensures the javascript files are consistent with this .jslintrc configuration file (you will need to add such a file to the repo as well).

Before pushing, install the necessary software locally, run the check locally, try to make the jslint check fail by temporarily adding some breaking style change to the JS files, ensure the check fails, then revert it and ensure the check passes again.

At that point you can add the check to the travis-ci configuration and send a PR to the repository.