ci-status with remote repository specification with -r

When local repository is like

* a-mine https://github.com/_username_/hub.git
* origin https://github.com/github/hub.git

and run `ci-status` fetches always from 'a-mine' remote build status.
This commit make it possible to choose remote repository's commit
build status with -r option like:

    hub ci-status -r origin __commit_sha__

You can also use -v option to retrieve build url

    hub ci-status -r origin __commit_sha__ -v