Docs job fails due to eventlet

[Nguyen Hai]

I'm working on add module index which builds autodoc for Tacker: https://bugs.launchpad.net/tacker/+bug/1761923

However, when building, it creates a warning, treated as error:
Please use pyroute2.config.asyncio.asyncio_config

It comes from the eventlet module, which will be drop soon. We should use asyncio_config instead.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/559464

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/559464
Committed: https://git.openstack.org/cgit/openstack/tacker/commit/?id=94d53dc596f778edf2883f82b60d83784d9953d9
Submitter: Zuul
Branch: master

commit 94d53dc596f778edf2883f82b60d83784d9953d9
Author: Nguyen Hai <email address hidden>
Date: Sat Apr 7 13:55:53 2018 +0900

    Switched to pyroute2.config.asyncio.asyncio_config

    To monkey patch socket module for pyroute2, we call eventlet_config.
    In recent releases of the library, this becomes deprecated. Instead, we
    should now use asyncio_config() to patch stdlib.

    When building module index for tacker docs, it creates a warning,
    treated as error: Please use pyroute2.config.asyncio.asyncio_config

    Closes-Bug: #1761925
    Change-Id: I8f21cfa02e1201f4968ec0ce1fb6865ef591678d