Updates the minimum version of Ansible from 2.5 to 2.6, and the maximum
supported version from 2.7 to 2.8.

Change-Id: I5aeb28424a8d1920b58ca73e37131d8cbfeabf29

Change-Id: Ia7d069bc49037c9961bce2a7814fae5745ae8a91

Updates the minimum version of Ansible from 2.4 to 2.5, and the maximum
supported version from 2.6 to 2.7.

Change-Id: If8071a9b5c85e5e69fbb333e91c84d10c20d80f3
Story: 2006143
Task: 35639

Using Kayobe with cliff 2.15.0 fails with the following error:

kayobe playbook run playbook.yml
invalid conflict_resolution value: 'ignore'

This change restricts cliff to <2.15.0.

Also, fix git cloning previous release repos in CI to allow this patch
to merge.

Zuul provides repositories with all branches containing all prospective
changes, not just the current branch. We can use this in the upgrade
jobs to include changes to the previous release branch when a patch
depends on them.

Change-Id: I7966cf33f6133090d83232504b8c1da4c7817e0c
Depends-On: https://review.opendev.org/665703/
Story: 2005891
Task: 33748

This new version makes the kayobe-tox-molecule job fail with:

    ImportError: cannot import name py31compat

Change-Id: Ieddf039483649cc7b575019409257b6ce5b3fb99

Bump the maximum supported version of Ansible to 2.6.x for both Kayobe
and Kolla Ansible.

Change-Id: Ia8691d127bb6ce57dcd6fdac25f0357844f5cbaa
Story: 2004287
Task: 27839

Raises the maximum Ansible version in requirements.txt to Ansible 2.5.x
for both kayobe and kolla ansible.

Also removes the hack to use a patched parted module for ceph block
device management, as Ansible 2.4 contains the required fix.

Change-Id: I0d2f564eb1ddb63b07829d6f0d918af26887db97
Story: 2001649
Task: 6668

Python Build Reasonableness (PBR) [1] is used by most OpenStack projects
for building python packages, so we should fall into line here.

[1] https://pypi.python.org/pypi/pbr

Change-Id: Ic74a62eeb65e7158ce75a082e68652c2e50a2a91
Story: #2001637
Task: #6648

Kayobe has a dependency on ansible, which is currently capped to 2.2. Docker has
decided to rename the docker-py python module to docker, and made some backwards
incompatible API changes to go along with it. Kolla-ansible requires us to use
docker (not docker-py) on the target hosts, but this is not supported for the
docker_container and docker_image ansible modules that kayobe uses with ansible
2.2. Upgrading to ansible 2.3 allows us to support the new docker python package.

Ansible 2.3 has been found not to work with some parts of kayobe.

Unit tests can be run via:

tox -e py27

Style checks can be run via:

tox -e pep8

The CLI replaces all existing shell scripts except for
configure-kayobe.sh. Other shell scripts are now removed.