Removes Ruby and uses Grunt for browser based tests.

This adds a server task to `grunt.js` and defines `grunt jasmine-browser`.

It spins up a server on port 8000, then you can go to [http://localhost:8000/BrowserRunner.html](http://localhost:8000/BrowserRunner.html) to see the tests.

To keep the server running, it's necessary to hook it with the `watch` task.

Only downside, it needs a separate `BrowserRunner.html` file, which is just identical to the one created with `npm test`, except that it doesn't include the phantom related scripts.