Add support for INFO field
Info fields now allow you to add information to git annex info <remote>. See #4
Usage: Just add a dict to your Remote object, eg self.info = {'username': "Jon"}
sha256sum AnnexRemote-1.2.0.tar.gz:
2b49b84e4e118e27af3cce7e22e1755f38d78bc4728fad7a8dd6ad307e372061