Newer Ansible versions will require at least Python 3.8 to be used,
and the build containers pipeline was requiring Python 3.6, which is
EOL.
This patch requests the latest Python version available for the
controller, and allows it to be configured to a specific version if,
and when, needed.
Without explicit installation, Ansible was failing to run on
Azure pipelines. This change explicitly install the latest
Ansible version available through `pip`.
Added a pipeline file (tests/azure/build-containers.yml) to build test
containers and upload them to quay.io. The pipeline will create
containers with IPA pre-installed for testing proposes on three
different Linux containers: CentOS 7, CentOS 8 and Fedora Latest.
