Feat/flavor checker direct

Created by: garloff

Rather than feeding the output from openstack flavor list -f value -c Name to flavor-name-check.py, we can create a tool that uses the openstacksdk to retrieve the flavor list and directly check. This has one big advantage: We get some data (like vCPUs and RAM and root disk size) from OpenStack and can compare it with what's advertized in a name. And indeed, found one warning (overprovided resources) on gx-scs and one error (underprovided resources) each on plus-pco and wavestack.

This gets us close to a complete conformance test for flavors.

Short of actually booting VMs and looking inside and doing long-term performance testing ...