'Create a role.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/identity/v2-ext/index.html#create-a-role'

def create_role(self, **kwargs):

    post_body = json.dumps({'role': kwargs})
    (resp, body) = self.post('OS-KSADM/roles', post_body)
    self.expected_success(200, resp.status)
    body = json.loads(body)
    return rest_client.ResponseBody(resp, body)
