code: func (r *Client) AddOrgUser(user UserRole, oid uint) (StatusMessage, error) {
  	var (
  		raw   []byte
  		reply StatusMessage
  		err   error
  	)
  	if raw, err = json.Marshal(user); err != nil {
  		return StatusMessage{}, err
  	}
  	if raw, _, err = r.post(fmt.Sprintf("api/orgs/%d/users", oid), nil, raw); err != nil {
  		return StatusMessage{}, err
  	}
  	err = json.Unmarshal(raw, &reply)
  	return reply, err
  }
docs: // AddUserToOrg add user to organization with id
  // It reflects POST /api/orgs/:orgId/users API call.