Comment 4 for bug 1697613

Reviewed: https://review.openstack.org/473721
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=8e8f721f6ff615bf43f8563e8940e4d46388c0e7
Submitter: Jenkins
Branch: master

commit 8e8f721f6ff615bf43f8563e8940e4d46388c0e7
Author: Akihiro Motoki <email address hidden>
Date: Tue Jun 13 07:29:39 2017 +0000

    Add libffi-dev to bindep.txt

    libffi-dev is required to install cffi and PyNaCL from tarballs.
    cffi is installed from requirements.txt, so 'test' profile is not
    specified.

    We usual use wheel packages when installing python packages,
    but tarball is sometimes used, for example, when a new version
    is uploaded. I think it is worth adding it to bindep.txt
    to avoid accidental gate failure.

    Closes-Bug: #1697613
    Change-Id: I4800c9f213fa5c8f28c8603e022264e6aa139090