title: Run PHPUnit tests on change
body: <p>I'd like to run my PHPUnit tests (or at least a subset of them) whenever a file changes on disk. Very similar to what you can do with "<a href="https://github.com/gruntjs/grunt-contrib-watch/blob/master/README.md">grunt watch</a>". I have a project in which I have both JS and PHP, and am using Grunt. There I shell out to PHPUnit to have it run on top of my JS tests using grunt watch. While that works just fine, it seems like an awful lot of hassle to do this in a PHP only project. I'd need to introduce grunt, and add a dependency on node. Plus I have a lot of such PHP projects. A more simple solution is thus in order.</p>