Mirror personal git repos used for Pluggable Transports

Some of the projects our software depends on is hosted in personal repos which are scattered across the web. We should probably mirror some of these on either git.tpo or gitlab.tpo (whichever makes more sense, but I'm leaning toward git.tpo right now) in case they disappear in the future.

I'm not sure how we should define the policy for when we self-host verses when we use the official repo. For example, the gocompress project for Tor Browser is cloned from a personal github repo. Is that worth mirroring?