neutron-sanity-check tool was importing neutron.tests.base module, which
may be not present on some systems (f.e. RDO splits neutron/tests/
subtree in a separate python-neutron-tests package). It made the tool
not usable in some setups.
https://bugzilla.redhat.com/show_bug.cgi?id=1374282
This is not the first time when we by mistake import from
neutron.tests.* and break distributions. It's time to stop it by
proactively forbidding that pattern via a new hacking check.
Some functions were moved from neutron.tests.base to
neutron.common.utils to fulfill the need requirement. They were moved
using debtcollector, no current consumers should be affected.
Closes-Bug: #1621782
Change-Id: I790777ddcbd1b02218b3db54ae3d5c931d72d4fa
31e1aeb66b