Update hacking for Python3

The repo is Python 3 now but still tests some older
branches, so update hacking to version 2.0 which
supports Python 2 and 3.

Fix problems found.

Change-Id: I54f1fa0ee72499a740e630bbd3478427babc2ec2
(cherry picked from commit d74b4383d82263a516b42aebf3745344661579d9)
(cherry picked from commit 5a3984de80ee166269a3ec5ba58b3efdc49e1afe)
diff --git a/test-requirements.txt b/test-requirements.txt
index c699d8c..8b421c6 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -3,5 +3,4 @@
 # process, which may cause wedges in the gate later.
 
 # Hacking already pins down pep8, pyflakes and flake8
-hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
-
+hacking>=2.0,<2.1.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index cf89710..5aa6b38 100644
--- a/tox.ini
+++ b/tox.ini
@@ -32,4 +32,7 @@
 [flake8]
 show-source = True
 builtins = _
+# W504 line break after binary operator
+# E741 ambiguous variable name 'l'
+ignore = W504,E741
 exclude=.venv,.git,.tox,*lib/python*,private,.eggs