The repo is Python 3 now, so update hacking to version 3.0 which
supports Python 3.

Fix problems found by updated hacking version.

Remove hacking and friends from lower-constraints, they are not needed
during installation.

Change-Id: I7ef5ac8a89e94f5da97780198619b6facc86ecfe

There is inconsistent use of either `/usr/bin/python` or
`/usr/bin/env python`. This makes for unexpected results when a
user might be using a virtualenv.

Change-Id: Ibb030f920a8869f9113ade70b66a921cc815060d

* Inspected each error and fixed / added nosec where appropriate.
* build-swift-ring.py which was throwing sec errors is no longer used so
  removed it.
* Removed the dev/ directory from being checked.

Closes-Bug: #1617713
Change-Id: I25664cabca4137e5c9f499c1af3f5ce78b86fb56

The "hacking" package used in most OpenStack repos pulls in
additional pep8 rules.  This commit should fix all of them
other than a hand full in the build.py file which will
be fixed in a separate commit

Change-Id: I40a0a30d338592ad64123e3da5523b9ad95a7a9c
Partially-Implements: blueprint enable-flake8

Change-Id: Ie6e77a4d45210122746b544a1aa8da563833e395
Partially-Implements: blueprint enable-flake8

This patch adds a script for validating YAML files, and replaces the
existing JSON checks with one largely identical to the YAML check.

This also provides a script that can be installed as a pre-commit hook
that will perform this checks when you commit changes.  You can install
the hook by running tools/pre-commit-hook --install.

Change-Id: Ib4742a9db062362cfa61d669c691151bc1ca376c