Clone or pull git repos doing only a spares checkout of the specified directory
Requires a hosts.txt file with following format:
https://github.com/foo/onething.git ./ui/dist,./admin-ui/build
https://gitlab.com/bar/something.git ./public
...
The format is REPO DIR1[,DIR2]...[,DIRn].
Sleeps for a minute after running, so just set it to restart=always and it'll update the repos every minute.