Return a list of available users (keystone user-list)

    CLI Example:

    .. code-block:: bash

        salt '*' keystone.user_list

def user_list(profile=None, **connection_args):
    '''
    Return a list of available users (keystone user-list)

    CLI Example:

    .. code-block:: bash

        salt '*' keystone.user_list
    '''
    kstone = auth(profile, **connection_args)
    ret = {}
    for user in kstone.users.list():
        ret[user.name] = dict((value, getattr(user, value, None)) for value in dir(user)
                              if not value.startswith('_') and
                              isinstance(getattr(user, value, None), (six.string_types, dict, bool)))
        tenant_id = getattr(user, 'tenantId', None)
        if tenant_id:
            ret[user.name]['tenant_id'] = tenant_id
    return ret