Way of development should be unifyed and scalable as for 1-3 developers, and also as for 10-20.
master branch should contain only pull requests merges, and only small group of people should have acces there (or better one, lets call this person Linus).
pull requests should pass review process, so far using github features, but if we think that this project wount die in next few mothes, we should switch to gerrit (f.e. https://review.gerrithub.io)
Way of development should be unifyed and scalable as for 1-3 developers, and also as for 10-20.
This way we will get few goals: