This commit enhances Shaker to allow:
- specifying a custom stack name, instead of always using a uniquely
generated one. This helps with tracking test stacks in CICD and/or
allowing users to be more descriptive when looking at running heat
stacks
- reusing an existing test stack, rather than re-stacking. This
is to allow the following scenario: Execute scenario A (setting
cleanup_on_error = false) to establish baseline data. Perform some
update in Openstack (config change, cert rotation, etc). Reuse the
existing VMs from the baseline test to re-execute scenario A to
help ensure the update had no impact.
Change-Id: Ifbdd332a44ca54f06cc81d9018ea5cea26c32416
8385ae1b97