Commits in quick succession can look like there was no previous stat

[davegaeddert]

Ideally it would know that the previous hasn't finished yet, and wait for it. But there isn't a "pending" state at this point for commitstat itself. That could be added but would be extra configuration that is annoying -- maybe instead it could just look that there are any pending builds/statuses, and if there is no commitstat yet then it can wait for all pending statuses to complete before considering it a failure?