'Update an image.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/image/v1/index.html#update-image'

def update_image(self, image_id, data=None, headers=None):

    if (headers is None):
        headers = {}
    if (data is not None):
        return self._update_with_data(image_id, headers, data)
    url = ('images/%s' % image_id)
    (resp, body) = self.put(url, None, headers)
    self.expected_success(200, resp.status)
    body = json.loads(body)
    return rest_client.ResponseBody(resp, body)
