code: func (s *OrganizationsService) PingHook(ctx context.Context, org string, id int64) (*Response, error) {
  	u := fmt.Sprintf("orgs/%v/hooks/%d/pings", org, id)
  	req, err := s.client.NewRequest("POST", u, nil)
  	if err != nil {
  		return nil, err
  	}
  	return s.client.Do(ctx, req, nil)
  }
docs: // PingHook triggers a 'ping' event to be sent to the Hook.
  //
  // GitHub API docs: https://developer.github.com/v3/orgs/hooks/#ping-a-hook