tox: use pip freeze with --all parameter
tox: use pip freeze with --all parameter

We need all possible package versions logged
when executing tests (locally or in CI), to be able
to debug issues.

By default 'pip freeze' excludes some packages (pip itself, setuptools
and such which make normally no sense to keep in requirements.txt).
But for offline-debug we need all versions logged, as also we do not use
pip freeze here for re-generation of requirements files.

Change-Id: I7c15823c1a233a16bc296b9108b7513a34d28251

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared