git prune-branches

@kevgo please review

+ Changed a couple git helpers to take in parameters instead of operating on the current branch
+ Set the default branch on the remote repo to main (needed as the git prune-branches feature specs were deleting the master branch (since its not main) and you cannot delete the HEAD branch on the remote repo.
I don't understand this. Doesn't `git checkout -b` already check out the new branch?