Add an option to run Chorme in docker

[hakubo]

This should allow for consistent results of comparison.

e.g. https://hub.docker.com/r/yukinying/chrome-headless/

https://github.com/LucianoGanga/simple-headless-chrome#using-a-docker-image

[mydea]

I'm not entirely sure what we'd need to change to allow this?

[hakubo]

Possibly just add documentation on how to do this. Haven't tried that yet though