Fixing merge reversion related to mitaka feature L7 tempest tests
Fixing merge reversion related to mitaka feature L7 tempest tests

Issues:
Fixes #383

Problem:
I reverted a bad merge (which I also made) and reverted changes related
to feature l7 tempest tests. Those changes need to be introduced to run
in nightly.

Analysis:
Added back the tox.ini file, the Makefile changes and the changes to
the tempest configuration and test scripts.

Tests:

F5Networks/f5-openstack-lbaasv2-driver,jlongstaf/f5-openstack-lbaasv2-driver,F5Networks/f5-openstack-lbaasv2-driver,mattgreene/f5-openstack-lbaasv2-driver,mattgreene/f5-openstack-lbaasv2-driver,jputrino/f5-openstack-lbaasv2-driver,jputrino/f5-openstack-lbaasv2-driver,jlongstaf/f5-openstack-lbaasv2-driver,richbrowne/f5-openstack-lbaasv2-driver,richbrowne/f5-openstack-lbaasv2-driver