Switch to Hacking 0.8.x

This brings along Hacking requirements to match
other OpenStack projects. Since hacking already
requires the right pep8 pyflakes etc version,
those dependencies are not necessary to be specified
here.

Change-Id: Ifb575aa549bfd0288e44acda9a750ea40b9d14c2
Merge "Switch to Hacking 0.8.x"