This test converts from mox to mock.
This partially aligns with upstream story 2001546
https://governance.openstack.org/tc/goals/rocky/mox_removal.html
As part of conversion, a mock host-list test was added
to help illustrate how to use mock and to increase code
coverage (which is now up to 35%)
Story: 2004515
Task: 28703
Change-Id: I58b1f2b271dd6dbf4faf07797444d1b51277c7bb
Signed-off-by: Al Bailey <Al.Bailey@windriver.com>