The repo uses docs-on-read-the-docs, remove extra
build-openstack-sphinx gate job.
Without this change, two docs jobs would be building in gate, tox-docs
and build-sphinx. One is enough.
Also, use templates instead of individual jobs.
Import other templates from project-config, use the failing docs
template since readthedocs is not setup yet.
Remove publish-to-pypi, this should stay in project-config.
Fix sphinx requirements for python 3.
Fix decoding in failing test.
Change-Id: Ic4f715b45c1284ea49339e96c2aa87b2e81fcbea
748aa2068b