Bump hacking

This change bumps hacking to 4.x and adds W503, W504, and W605 to the
ignore list for now.

Change-Id: I2b5c7c671b1cd7c0f378992895434f86b02ed95e

test-requirements.txt

@@ -1,7 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
+hacking>=4.0.0,<4.1.0 # Apache-2.0
 
 coverage!=4.4,>=4.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD

tox.ini

@@ -34,6 +34,9 @@ commands = {posargs}
 
 [flake8]
 # H405  multi line docstring summary not separated with an empty line
-ignore = H405
+# W503 line break before binary operator
+# W504 line break after binary operator
+# W605 invalid escape sequence
+ignore = H405,W503,W504,W605
 exclude = .venv,.tox,dist,doc,*.egg,./os_collect_config/openstack/*
 show-source = true