Possibility to select chrome/canary

[stepnivlk]

I think it would be quite helpful to be able to select which chrome I want to run (stable/canary), something like:

{:ok, pid} = ChromeLauncher.launch([remote_debugging_port: 9233, canary: true])

what do you think @andrewvy ?

[andrewvy]

Hi! I think this may be difficult for detecting which chrome installations are installed on the host machine, https://github.com/andrewvy/chrome-launcher/blob/master/lib/finder.ex is still not the greatest.

For your cases, you can also provide a CHROME_PATH environment variable to the desired executable. Let me know if that works, or if you desire running different types of chrome versions at the same time.