Update hacking for Python3

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

Fix problems found.

Change-Id: Ib7870977e5aa66d1eb2e41d698ed058ebb65b4c1

tempest_stress/driver.py

@@ -142,7 +142,7 @@ def stress_openstack(tests, duration, max_runs=None, stop_on_error=False):
         if test.get('use_admin', False):
             manager = admin_manager
         else:
-            raise NotImplemented('Non admin tests are not supported')
+            raise NotImplementedError('Non admin tests are not supported')
         for p_number in range(test.get('threads', default_thread_num)):
             if test.get('use_isolated_tenants', False):
                 username = data_utils.rand_name("stress_user")

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<0.12,>=0.11.0 # Apache-2.0
+hacking>=3.0,<3.1.0 # Apache-2.0
 
 coverage>=3.6 # Apache-2.0
 stestr>=1.0.0 # Apache-2.0

tox.ini

@@ -49,6 +49,6 @@ commands = oslo_debug_helper {posargs}
 # E123, E125 skipped as they are invalid PEP-8.
 
 show-source = True
-ignore = E123,E125
+ignore = E123,E125,W503,W504
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build