GitHub Commit Status: Single check for all groups

• Having a commit status check for each project run can be too noisy.

• Some customers are only interested in knowing whether any of the groups failed.

Desired:

• A single check "Current Tests" for all 3 groups.

Notes:

• This might be a more common scenario with users that have one project for their main test suites, and additional projects for "setup"/"teardown".

• Having the groups' execution details outlined in the PR comment is useful and shouldn't be changed.