That's great, thanks! I hate creating the github repo as well (sometimes I skip that part and just use Heroku). If you don't mind I'll copy some of your code and make creating a github repo another optional prompt.
I noticed that suspenders(thoughtbot) also had that option. They used hub, which I think is a bit more intrusive than just installing the octokit gem. I'm interested to see what you come up with! :)