
The repo is Python using both Python 2 and 3 now, so update hacking to version 2.0 which supports Python 2 and 3. Note that latest hacking release 3.0 only supports version 3. Fix problems found. Remove hacking and friends from lower-constraints, they are not needed for installation. Change-Id: I9bd913ee1b32ba1566c420973723296766d1812f