Update hacking for Python3

The repo is Python 3 now, so update hacking to version 2.0 which
supports Python 3.

Blacklist:
W504 line break after binary operator

Fix:
E305 expected 2 blank lines after class or function definition, found 1

Change-Id: I713186061d5484ee2cd5317eb9192646fd3a1099

osc_lib/tests/command/test_commandmanager.py

@@ -28,6 +28,7 @@ class FakeCommand(object):
     def __init__(self):
         return
 
+
 FAKE_CMD_ONE = FakeCommand
 FAKE_CMD_TWO = FakeCommand
 FAKE_CMD_ALPHA = FakeCommand

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<0.11,>=0.10.0
+hacking>=2.0,<2.1 # Apache-2.0
 
 coverage!=4.4,>=4.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD

tox.ini

@@ -60,7 +60,7 @@ show-source = True
 exclude = .git,.tox,dist,doc,*lib/python*,*egg,build,tools
 # If 'ignore' is not set there are default errors and warnings that are set
 # Doc: http://flake8.readthedocs.org/en/latest/config.html#default
-ignore = __
+ignore = W504
 
 [testenv:lower-constraints]
 deps =