According to the configuration reference,
http://docs.openstack.org/mitaka/config-reference/compute/resize.html
When using KVM, nova utilizes SSH for instance resizing.
Kolla nova_ssh container has the nova user configured with "/sbin/nologin" shell,
which prevents nova_compute from successfully resizing instances.
Added fix to change shell from nologin to bash.
Change-Id: I46a48e242dae6ee6c9159bc30edd8b823ffbb515
Closes-Bug: 1617902
Add a nova-ssh container to handle the `nova migrate` and
`nova resize` case, in which the nova will use ssh to copy
files between machines.
Change-Id: Ie6675943f3aeabfbba8589d308d55b9c89d732db
Closes-Bug: #1562141