Add test_validate_config
Add test_validate_config

The validate_config script was moved from openstack-recipes
in a previous commit but the test module was not.
This moves the test module as well.

Change-Id: Iaac2ee2483531aa829e6b82e2d383e3b294a4f9a

open-power-ref-design-toolkit/os-services,open-power-ref-design/os-services,open-power-ref-design/os-services,open-power-ref-design-toolkit/os-services,open-power-ref-design-toolkit/os-services