Always sync before to-master

[jdigger]

Right now if you do something like

$ git sync
$ git rebase -i  # squash commits
$ git to-master

When it does the to-master it will close the original branch/PR, but it will look "disconnected" in GitHub.

If instead you do

$ git rebase -i  # squash commits
$ git sync
$ git to-master

The process of doing the to-master will be a simple fast-forward, so it will appear as a simple (fast-forwarded) merge to GitHub and its PR. It provides a much cleaner and easy to follow experience.