This is tested implicitly in the `add_user_to_repo` tests; `add_user_to_org` is also private. Do you think we should write some tests for `add_user_to_org`?

But yeah, I agree that there's a lot going on in this method. Plus it's private and not everything it does falls strictly within the domain of interacting with the GitHub API. It would be nice if we could extract some of the behavior in all these private methods into a class or two with testable public methods.