Further Cleanup py27 support

This repo is now testing only with Python 3, so let's make
a few cleanups:
- Remove obsolete sections from setup.cfg
- Use newer openstackdocstheme,reno and Sphinx versions
- Remove install_command from tox.ini, the default is fine
- Use TOX_CONSTRAINTS_FILE, UPPER_CONSTRAINTS_FILE is obsolete
- Update hacking to 3.0.1, fix warnings found
- Remove babel.cfg, it's not needed anymore

Change-Id: I60edb7e44e4a8222f564f30157eb31288b85b422

1 files changed, 7 insertions, 5 deletions

diff --git a/tox.ini b/tox.ini
index edea05d..65779fe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-minversion = 1.8
+minversion = 3.1.1
 envlist = py38,pypy,pep8,releasenotes
 skipsdist = True
 ignore_basepython_conflict = True
@@ -7,16 +7,16 @@ ignore_basepython_conflict = True
 [testenv]
 basepython = python3
 usedevelop = True
-install_command = pip install {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/requirements.txt
+deps =
+       -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+       -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-       -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
 commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
-deps = hacking>=0.12,<0.13
+deps = hacking>=3.0.1,<3.1.0
 commands = flake8
 
 [testenv:venv]
@@ -42,4 +42,6 @@ commands = sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenote
 
 [flake8]
 show-source = True
+# W503 line break before binary operator
+ignore = W503
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build