In reviews we usually check import grouping but it is boring.
By using flake8-import-order plugin, we can avoid this.
It enforces loose checking so it sounds good to use it.
This flake8 plugin is already used in tempest.
Note that flake8-import-order version is pinned to avoid unexpected
breakage of pep8 job.
Setup for unit tests of hacking rules is tweaked to disable
flake8-import-order checks. This extension assumes an actual file exists
and causes hacking rule unit tests.
Change-Id: I12b596820727aeeb379bee16c2bc993dee9eb637
this will better isolate the unit tests from the functional tests.
unfortunately, the "integration" tests had to be lumped into the
"unit" tests since we need the separation in testr.conf
Change-Id: Ifd12198c1f90e4e3c951c73bfa1884ab300d8ded