The repo is Python 3 now, so update hacking to version 3.0 which
supports Python 3.
Fix problems found.
Update local hacking checks for new flake8.
Remove hacking and friends from lower-constraints, they are not needed
to be installed at run-time.
Change-Id: Ia6af344ec8441dc98a0820176373dcff3a8c80d5
The datasources are only used by the decision_engine, however, they
are placed in a directory one level higher. This patch moves the
datasources code into the decision_engine folder.
Change-Id: Ia54531fb899b79a59bb77adea079ff27c0d518fa
