Add multi-cell negative test for cold migration with target host
Add multi-cell negative test for cold migration with target host

This adds a functional test which runs two cells, one host per
cell, and attempts to cold migrate an instance from the host
in one cell to the host in the other cell, which fails in the
API with ComputeHostNotFound because the context is targeted
to the cell where the instance lives, so it won't be able to
find the targeted host in the other cell.

Co-Authored-By: Matt Riedemann <mriedem.os@gmail.com>

Part of blueprint cold-migration-with-target-queens

Change-Id: I76db5a6cd38c3c407102d8dc03beb6a4db782454

openstack/nova,mikalstill/nova,rahulunair/nova,klmitch/nova,gooddata/openstack-nova,rahulunair/nova,mikalstill/nova,klmitch/nova,mahak/nova,mahak/nova,gooddata/openstack-nova,klmitch/nova,mahak/nova,klmitch/nova,gooddata/openstack-nova,gooddata/openstack-nova,openstack/nova,mikalstill/nova,phenoxim/nova,rahulunair/nova,phenoxim/nova,openstack/nova