[Noted by @Susurrus](https://github.com/nix-rust/nix/pull/536#issuecomment-294316385). I'm considering attempting to move us to [bors-ng](https://github.com/bors-ng/bors-ng) which has some additional features on top of bors / homu: - it's actively maintained - it can batch PRs to merge multiple with one CI run