Add scenario test: test instances with cinder volumes

This patch adds a scenario test instances with cinder volumes launches
on all available compute nodes, up to CONF.compute.min_compute_nodes.
Also 1 additional configuration is added: volume_types_for_data_volume.

Also function for create and add security group to server is moved
to tempest/scenario/manager.py to avoid code duplication.

Change-Id: I346a9505bc942e66aedad2029215617d0918a885
5 files changed