We currently install ansible during the pre_command phase in tox. This
breaks the following use case:
tox -e py36 --notest
ttrun <test case>
This is broken now because ttrun doesn't run pre_commands. Instead we
already have a pip wrapper that does the nodeenv installation. We can
use this to also call zuul-manage-ansible on zuul installation.
Change-Id: I680777e5406368d35366602ac37e029db91c8a5c