Fork into organization

It looks like the js api doesnt support forking into an organization even those the REST api supports it.

https://developer.github.com/v3/repos/forks/#create-a-fork

http://github-tools.github.io/github/docs/3.1.0/Repository.html#fork

Can this be added? Thanks!

Start with the Repository#fork documentation and the linked REST API documentation, then locate the JavaScript API's fork entry point. Confirm how the current method accepts fork options and compare them with the REST API's organization support. Done means the JavaScript API can fork into an organization consistently with the documented REST behavior.

索引モデルが issue の本文から書いたものです。