bump hacking min version to 3.0.1 in test-requirement

flake8 new release 3.8.0 added new checks and gate pep8
job start failing. hacking 3.0.1 fix the pinning of flake8 to
avoid bringing in a new version with new checks.

Though it is fixed in latest hacking but 2.0 and 3.0 has cap for
flake8 as <4.0.0 which mean flake8 new version 3.9.0 can also
break the pep8 job if new check are added.

To avoid similar gate break in future, we need to bump the hacking min
version.

- http://lists.openstack.org/pipermail/openstack-discuss/2020-May/014828.html

Trivial change

Change-Id: I7728b8f6e8dc93c6494b69ad1eb1ee99c79a6f78

test-requirements.txt

@@ -2,7 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=1.1.0,<1.2.0 # Apache-2.0
+hacking>=3.0.1,<3.1.0 # Apache-2.0
 # remove this pyflakes from here once you bump the
 # hacking to 3.2.0 or above. hacking 3.2.0 takes
 # care of pyflakes version compatibilty.

tox.ini

@@ -43,6 +43,6 @@ show-source = True
 # F405 TEMPLATES may be undefined, or defined from star imports
 # (because it is not easy to avoid this in openstack_dashboard.test.settings)
 # H405 multi line docstring summary not separated with an empty line
-ignore = F405,H405
+ignore = F405,H405,W504
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,.ropeproject,tools,releasenotes,.tmp