Change-Id: I8b4e649e24871b1191dba39d766b6c133c7e8f24

2020 is coming, everyone should be using Python 3 now.

As per the official python support timeline set forth by the OpenStack
TC [1], OpenStack Train (in our case, kolla-ansible 9.x) is the last
release that will support python2.7.

[1] https://governance.openstack.org/tc/resolutions/20180529-python2-deprecation-timeline.html

Implements: blueprint drop-py2-support

Change-Id: Ibb3b12a779ecfd424053d0b3e98dac2f21d909bc

We should probably have had this in previously.

Change-Id: I14f690194085729bf500ed707d3bb99b1c055845

Co-Authored-By: Jeffrey Zhang <jeffrey.zhang@99cloud.net>
Closes-Bug: #1638895
Change-Id: Ieeb6a795a3b0295e1b8c7137c08626550317ec01

Ansible>2 dependes on gcc, python-devel and openssl-devel

Closes-Bug: #1626861
Change-Id: Ib881a7642f136bf72f2ce167cf983ec1b5b13d0c

bindep installs a slew of stuff we don't really need and doesn't add
much if any value.  This only turns on bindeps that are required.

This shaves about 3 minutes off each gate run.

Closes-Bug: #1620865
Change-Id: I24df4f2a30c682c1b09e89c7c52f7608582da1a6