Nova now implements two major changes wrt: CellsV2 and Placement.
We need to properly document them in the release notes in order to help
our operators.
Co-Authored-By: Dan Smith <dansmith@redhat.com>
Depends-On: Ia0869dc6f7f5bd347ccbd0930d1d668d37695a22
Change-Id: Ie3eace8c851edcdbb2095e9550caab296109b4b8