Create AnsibleZuulTestCase

This test case base class maintains the current test case base
class behavior in v3, which is to run the actual ansible launcher.
However, that's not needed for all of the scheduler tests, some
of which want to have complete control of jobs in a way which may
be difficult in ansible.  Create this new test case base class so
that tests where we know we want to exercise ansible are easy, but
if we don't need it, we get the Zuul v2 behavior of a fake worker.

Change-Id: I836fec935979d90eb0eb3ca765c87bc8300920aa
2 files changed