Cleanup py27 support

Make a few cleanups:
- Remove obsolete sections from setup.cfg
- Cleanup doc/source/conf.py to remove now obsolete content.
- Use newer openstackdocstheme version
- Remove install_command from tox.ini, the default is fine;
  cleanup tox.ini for python3

Change-Id: I306fe1dd080839004e206ac08f3526812e406f19

doc/requirements.txt

@@ -6,7 +6,7 @@ sphinx>=1.6.2 # BSD
 actdiag
 blockdiag
 nwdiag
-openstackdocstheme>=1.20.0 # Apache-2.0
+openstackdocstheme>=1.32.1 # Apache-2.0
 seqdiag
 sphinxcontrib-actdiag
 sphinxcontrib-blockdiag # BSD

doc/source/conf.py

@@ -12,9 +12,6 @@
 # serve to show the default.
 
 import datetime
-import subprocess
-import sys
-import os
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -28,7 +25,7 @@ import os
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.autodoc',
+extensions = [
               'sphinx.ext.todo',
               'sphinx.ext.viewcode',
               'sphinxcontrib.blockdiag',

setup.cfg

@@ -10,12 +10,3 @@ classifier =
     Intended Audience :: Developers
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
-
-[build_sphinx]
-all_files = 1
-build-dir = doc/build
-source-dir = doc/source
-warning-is-error = 1
-
-[wheel]
-universal = 1

tox.ini

@@ -4,13 +4,13 @@ envlist = docs,py36
 skipsdist = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 setenv =
   VIRTUAL_ENV={envdir}
   OS_LOG_CAPTURE={env:OS_LOG_CAPTURE:true}
   OS_STDOUT_CAPTURE={env:OS_STDOUT_CAPTURE:true}
   OS_STDERR_CAPTURE={env:OS_STDERR_CAPTURE:true}
-install_command = pip install -U {opts} {packages}
 # Unit test requires docutils and it is recommended to install docutils via
 # sphinx. We use doc/requirements.txt as well to avoid duplicated entries.
 deps =
@@ -19,11 +19,9 @@ deps =
 commands = stestr run --slowest {posargs}
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:docs]
-basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt