Shameless plug: I've been hacking on headless chrome in AWS Lambda but with selenium webdriver support [1], also using the binaries from the serverless-chrome [2] project.

To echo another comment on this thread, headless chrome seems well-positioned to shake up the automated browser testing market. The price—especially with the AWS Lambda free tier—is very, very compelling for a number of projects.

[1] https://github.com/smithclay/lambdium [2] https://github.com/adieuadieu/serverless-chrome