Baseline changes to comply with Release Notes Management
based in Reno [0]:
* Use build-openstack-releasenotes job for release notes
(We can't use the OpenStack releasenotes template as it includes
publish jobs, stx needs its own)
* Add newnote tox environment as convenience for creating new release
notes, re-using the releasenotes venv.
* Remove the unused 'true' tox environment.
[0] https://docs.openstack.org/reno/latest/
Story: 2003101
Task: 26620
Change-Id: Ie0eac726983f8cdfb6bade20a2b5445559a962e0
Signed-off-by: Abraham Arce <abraham.arce.moreno@intel.com>
Abraham Arce