fix(git): make branchName optional

[kkruit]

fixes issue #25

[caitp]

Great! By the way, you don't always have to create new PRs, you can pull commits into a different branch for a different PR with git cherry-pick <SHA>, and you can remove commits from the current branch with git rebase -i HEAD~<some number> and just delete the lines with commits you don't want, and then just force-push your update.

It's nice because it means fewer issues are opened and there's less zig-zagging around. Anyways, I think we can merge this, once travis is green

[kkruit]

Awesome. I haven't used cherry-pick. I think it was all one commit so that would have been an issue but keeping that in mind that will come in handy. Thanks!