I started https://GitHub.com/GitJournal/git-auto-sync to do this exact thing. Just with an easier interface and proper tests.

You can basically call `git-auto-sync daemon add`, and it will register itself as a systemd user process (on Linux, other OSs are also supported), and monitor that folder for changes + poll every x minutes.

It's still in the early stages, but I'd love to get your feedback.

Edit: Or you can just call `git-auto-sync sync` to commit + pull / rebase + push.