Add functional test for rescheduling during a migration
Add functional test for rescheduling during a migration

This adds a functional test which recreates the bug where
the allocations on a destination node are not removed from
Placement before rescheduling during a cold migrate operation,
which is the same code flow as a resize even though resize
isn't explicitly tested here.

Change-Id: I1e3def1e98d0008240837eb1ad0eaa81a9b2d189
Related-Bug: #1712850

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