We intend to add support for MAAS, another bare metal provisioning
and management service.
Note that the tox job fails at the moment as "whitelist_externals"
has been deprecated in favor of "allowlist_externals", so we'll
need to address that as well.
Another issue that we need to fix is that sphinx is unable to
locate some image files:
/home/zuul/src/opendev.org/openstack/watcher-specs/doc/source/
specs/newton/implemented/scoring-module.rst:232: WARNING: image
file not readable: doc/source/images/scoring-module-deployment.png
Change-Id: I54b3c578f677ad7d554732a5018163e4780f9457
ea19cfd56e