'Detaches a volume from a server instance.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/compute/#detach-a-volume-from-an-instance'

def detach_volume(self, server_id, volume_id):

    (resp, body) = self.delete(('servers/%s/os-volume_attachments/%s' % (server_id, volume_id)))
    self.validate_response(schema.detach_volume, resp, body)
    return rest_client.ResponseBody(resp, body)
