List roles

    CLI Example:

    .. code-block:: bash

        salt '*' keystoneng.role_list
        salt '*' keystoneng.role_list domain_id=b62e76fbeeff4e8fb77073f591cf211e

def role_list(auth=None, **kwargs):
    '''
    List roles

    CLI Example:

    .. code-block:: bash

        salt '*' keystoneng.role_list
        salt '*' keystoneng.role_list domain_id=b62e76fbeeff4e8fb77073f591cf211e
    '''
    cloud = get_operator_cloud(auth)
    kwargs = _clean_kwargs(**kwargs)
    return cloud.list_roles(**kwargs)