Makefile/Dependency/VC fixes

Couple of small fixes. Make wasn't working for me because the command that attempted to modify `$PATH` wasn't working. Also, once I fixed that and ran `make serve` I noticed that I would get an error saying a dependency was missing so I added that to `.gitignore`. Finally, `public/js/chirp.js` seemed to already be under VC before it was added to gitignore, so I `git rm`'d it.