code: func (s *RepositoriesService) UpdateRequiredStatusChecks(ctx context.Context, owner, repo, branch string, sreq *RequiredStatusChecksRequest) (*RequiredStatusChecks, *Response, error) {
  	u := fmt.Sprintf("repos/%v/%v/branches/%v/protection/required_status_checks", owner, repo, branch)
  	req, err := s.client.NewRequest("PATCH", u, sreq)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	sc := new(RequiredStatusChecks)
  	resp, err := s.client.Do(ctx, req, sc)
  	if err != nil {
  		return nil, resp, err
  	}
  
  	return sc, resp, nil
  }
docs: // UpdateRequiredStatusChecks updates the required status checks for a given protected branch.
  //
  // GitHub API docs: https://developer.github.com/v3/repos/branches/#update-required-status-checks-of-protected-branch