Get The Combined Status For Specific Reference

Users with pull access in a repository can access a combined view of commit statuses for a given ref. The ref can be a SHA, a branch name, or a tag name. Additionally, a combined `state` is returned. The `state` is one of: * **failure** if any of the contexts report as `error` or `failure` * **pending** if there are no statuses or a context is `pending` * **success** if the latest status for all contexts is `success`