Update hacking for Python3

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

Fix problems found.

Remove hacking and friends from lower-constraints, they are not needed
for installation.

Change-Id: I76369aad2778418182eab7c3eaf331b8d6b8fb1d

lower-constraints.txt

@@ -9,11 +9,9 @@ dulwich==0.15.0
 eventlet==0.18.2
 extras==1.0.0
 fixtures==3.0.0
-flake8==2.5.5
 gitdb==0.6.4
 GitPython==1.0.1
 greenlet==0.4.10
-hacking==0.12.0
 imagesize==0.7.1
 iso8601==0.1.11
 Jinja2==2.10
@@ -34,9 +32,7 @@ oslo.serialization==2.18.0
 oslo.utils==3.33.0
 oslotest==3.2.0
 pbr==2.0.0
-pep8==1.5.7
 psutil==3.2.2
-pyflakes==0.8.1
 Pygments==2.2.0
 pyparsing==2.1.0
 python-mimeparse==1.6.0

oslo_reports/tests/test_guru_meditation_report.py

@@ -147,7 +147,7 @@ class TestGuruMeditationReport(base.BaseTestCase):
         curr_line += len(target_str_p_head)
 
         # followed by at least one process
-        self.assertTrue(re.match("Process \d+ \(under \d+\)",
+        self.assertTrue(re.match(r"Process \d+ \(under \d+\)",
                                  report_lines[curr_line]))
 
         # followed by some more process stuff

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,<3.1.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 stestr>=2.0.0 # Apache-2.0
 

tox.ini

@@ -38,8 +38,9 @@ commands = python setup.py test --coverage --coverage-package-name=oslo_reports
 
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.
+# W504 line break after binary operator
 show-source = True
-ignore = E123,E125
+ignore = E123,E125,W504
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build