'resize and confirm_resize an server, waits for it to be ACTIVE.'

@classmethod
def resize_server(cls, server_id, new_flavor_id, **kwargs):

    cls.servers_client.resize_server(server_id, new_flavor_id, **kwargs)
    waiters.wait_for_server_status(cls.servers_client, server_id, 'VERIFY_RESIZE')
    cls.servers_client.confirm_resize_server(server_id)
    waiters.wait_for_server_status(cls.servers_client, server_id, 'ACTIVE')
