Use latest version of phantomjs

Is there any reason why the phantomjs is pinned to an older version (`1.9.1-0`)? I have tested it with the latest version (as per this patch) and it all seems to work fine.

PhantomJS `1.9.1-9` introduces a fix I contributed which prevents errors upon running `npm install` where multiple package transitively depend on the phantomjs package. For instance, if both grunt-casperjs and karma-phantomjs-launcher are present, the installation would randomly fail due to a race condition bug.