sg: draft a test runner for setup command
Created by: jhchabran
Follow-up to https://github.com/sourcegraph/sourcegraph/pull/29228 that I hacked on the other day.
This is the first attempt to provide a test runner for sg setup
. Testing the checks is perfectly doable if we don't mind waiting for the installation process. Docker is obviously an issue and needs a workaround or to leave it as it.