Cleanup py27 support

This repo is now testing only with Python 3, so let's make
a few cleanups:
- Add requires on python >= 3.6 to setup.cfg so that pypi and pip
  know about the requirement
- Remove obsolete sections from setup.cfg
- Update requirements, no need for python_version anymore
- Use newer openstackdocstheme and Sphinx versions
- Remove install_command from tox.ini, the default is fine
- Remove babel.cfg, it's not needed
- move basepython into testenv

Change-Id: I4c0e3b9b12c6b46c3b6b6a2f8f96e6996421dd8d

babel.cfg

@@ -1 +0,0 @@
-[python: **.py]

requirements.txt

@@ -2,4 +2,4 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-pbr>=0.5.21,<1.0
+pbr!=2.1.0,>=2.0.0 # Apache-2.0

setup.cfg

@@ -7,6 +7,7 @@ author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 license = Apache License (2.0)
 home-page = https://opendev.org/openstack/tripleo-puppet-elements
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Development Status :: 3 - Alpha
@@ -18,11 +19,3 @@ classifier =
 [files]
 data_files =
     share/tripleo-puppet-elements = elements/*
-
-[wheel]
-universal = 1
-
-[build_sphinx]
-all_files = 1
-build-dir = doc/build
-source-dir = doc/source

test-requirements.txt

@@ -5,9 +5,8 @@
 hacking>=3.0,<3.1.0 # Apache-2.0
 oslotest
 
-sphinx>=1.8.0,<2.0.0;python_version=='2.7' # BSD
-sphinx>=1.8.0,!=2.1.0;python_version>='3.4' # BSD
-openstackdocstheme>=1.20.0 # Apache-2.0
+sphinx>=2.0.0,!=2.1.0 # BSD
+openstackdocstheme>=2.0.0 # Apache-2.0
 testrepository>=0.0.18
 
 # This is required for the releasenotes build jobs

tox.ini

@@ -1,24 +1,23 @@
 [tox]
-minversion = 2.0
+minversion = 3.1.1
 skipsdist = True
-envlist = pep8,py27,py37
+envlist = pep8,py36,py37
+ignore_basepython_conflict = True
 
 [testenv]
 usedevelop = True
-install_command = pip install {opts} {packages}
+basepython = python3
 deps =
-       -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+       -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
        -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands=
     python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:pep8]
-basepython = python3
 commands = ./run-flake8
 
 [flake8]
@@ -27,5 +26,4 @@ exclude = .venv,.tox,dist,*.egg,build,releasenotes
 show-source = true
 
 [testenv:releasenotes]
-basepython = python3
 commands = bash -c tools/releasenotes_tox.sh