Pagination for RepositoryListForks

```
curl -s -D - -o /dev/null https://api.github.com/repos/joyent/node/forks | grep ^Link
```
```
Link: <https://api.github.com/repositories/211666/forks?page=2>; rel="next", <https://api.github.com/repositories/211666/forks?page=220>; rel="last"
```