git: implement UpdateRef{,Reason}
git: implement UpdateRef{,Reason}

Jericho25/-git-lfs_miilkyway,dakotahawkins/git-lfs,Jericho25/-git-lfs_miilkyway,github/git-lfs,dakotahawkins/git-lfs,aleb/git-lfs,github/git-lfs,aleb/git-lfs,dakotahawkins/git-lfs,aleb/git-lfs,github/git-lfs,Jericho25/-git-lfs_miilkyway