Use built in cleanup for servers in test_large_ops

The  scenario base class has code  to properly clean up servers and
wait until they are fully deleted.  Use this instead of custom cleanup
which doesn't wait for delete to complete.

Change-Id: Ic9fe5ea0d267116d5bc78f50d1945602e5247d6a
Add some test-cases for cinder cli

Add some omitted test-cases for cinder-cli in tempest

 + test_cinder_credentials
 + test_cinder_availability_zone_list
 + test_cinder_endpoints
 + test_cinder_service_list
 + test_cinder_transfer_list
 + test_cinder_bash_completion

Change-Id: I2d05fa0fb1421c292097c19643ed22f221a0d349
Merge "Add some test-cases for cinder cli"
Merge "Use built in cleanup for servers in test_large_ops"