Upgrade phantom.js

[ginatrapani]

Adam says: "Every now and then I'd been checking whether phantomjs 2.0 had been released, and today someone commented on a slimerjs issue I'd filed, which reminded me to check, and... it has updated!

http://phantomjs.org/release-2.0.html

So, I dunno, if you were at interested in trying it out for the insight2png thing, they're mostly drop-in replacements (can't remember if there are any calls in there that are slimer-specific, but if there are, it's only like one or two). Might be worth looking into, unless things are going a-okay all around for the slimer stuff."