We will waste about a minute during tests if the resource groups don't exist

[yaronyg]

When we try to delete the resource groups at the start of a test the delete will fail if the resource groups don't exist. But we will just consume that error and retry 60 times and then only then actually return the failure to delete a non-existent group error which will then be consumed and ignored. So ideally we would enhance runAzCommand with the ability to say "If you see this error then just return immediately, it's o.k. (or it's bad)."