Being able to select browser versions.

[chrisdenman]

Is your feature request related to a problem? Please describe.
Currently we are at the mercy of Selenium (remote) as to what browser versions are used to test the site. This is a good first step but is not suitable for reproducing problems from other users.

Describe the solution you'd like
Being able to select browser versions in our config. This should look something like:

"targets": [
        {
          "name": "chrome",
          "version": "129.121.122.1"
        }
      ]