Integration with upsource

Upsource does not have a pull request system on it's own, it is more of a code review tool, but I guess that should be no problem.

I would like to implement this, but I have a bit of a hard time to figure out where to get started.
Are the methods found in https://github.com/danger/danger-js/blob/master/source/platforms/FakePlatform.ts what a possible upsource connector should implement?