PhantomJS no longer being maintained, switch to chrome headless instead

[Brian Smith]

PhantomJS no longer being maintained, switch to chrome headless instead.

PhantomJS announcement: ariya/phantomjs#15344
Chrome headless: https://github.com/GoogleChrome/puppeteer

[Matt Mueller]

Agreed, I'd like this to be the first thing that's done. A chrome headless driver for x-ray. See: #252

[Al Johri]

found this attempt on googling: https://github.com/brandonmp/x-ray-puppeteer