Add python-octavia-tests-golang to stein-testing
Add python-octavia-tests-golang to stein-testing

The python-octavia-tests-golang subpackage of octavia
(or octavia-tempest-plugin) is only built for the x86_64 arch in
RDO Trunk. To allow altarch users to install the package without
getting dependency errors, we are adding a CBS build to the
dependency repo.

As shown in [1], the package is built for aarch64 and ppc64le.

[1] - https://cbs.centos.org/koji/taskinfo?taskID=564035

Change-Id: I08c31317fdec9bd2abe1dc7f09222e78f19efed7

redhat-openstack/rdoinfo,javierpena/rdoinfo