I wrote and released a similar concept in 2012 in response to co-workers constantly breaking my code and not running tests before committing. https://rubygems.org/gems/git_test/
That was before we had a reliable CI server and let me tell you, fixing the CI server was a much better investment than convincing everyone to run and document their tests locally. The basecamp tool is more polished than what I cobbled together, but I personally won’t be reaching for it any time soon.
It's actually worse than that; this tool doesn't run any tests or do anything with test results. All it does is require each developer to run `gh signoff` before their PR can be merged; the only thing that command checks is that there aren't uncommitted changes in Git. So if your colleagues aren't already locally running your tests the right way, this does nothing at all to help you.