Cleanup py27 support

This repo is now testing only with Python 3, so let's make
a few cleanups:
- Remove obsolete section from setup.cfg
- Use newer openstackdocstheme and Sphinx version for python 3
- Remove install_command from tox.ini, the default is fine
- Move basepython into testenv
- Update bashate version

Change-Id: I3d78b3787af2efce831d223dbcab6cf84c358028

doc/requirements.txt

@@ -2,8 +2,8 @@ pbr>=2.0.0,!=2.1.0
 
 Pygments
 docutils
-sphinx>=1.6.2
-openstackdocstheme>=1.20.0
+sphinx>=2.0.0,!=2.1.0
+openstackdocstheme>=2.0.0
 nwdiag
 blockdiag
 sphinxcontrib-blockdiag

setup.cfg

@@ -10,6 +10,3 @@ classifier =
     Intended Audience :: Developers
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
-
-[wheel]
-universal = 1

tox.ini

@@ -5,15 +5,14 @@ envlist = bashate
 
 [testenv]
 usedevelop = False
-install_command = pip install {opts} {packages}
+basepython = python3
 
 [testenv:bashate]
-basepython = python3
 # if you want to test out some changes you have made to bashate
 # against devstack, just set BASHATE_INSTALL_PATH=/path/... to your
 # modified bashate tree
 deps =
-   {env:BASHATE_INSTALL_PATH:bashate==0.5.1}
+   {env:BASHATE_INSTALL_PATH:bashate==2.0.0}
 whitelist_externals = bash
 commands = bash -c "find {toxinidir}             \
          -not \( -type d -name .?\* -prune \)    \
@@ -35,7 +34,6 @@ commands = bash -c "find {toxinidir}             \
          -print0 | xargs -0 bashate -v -iE006 -eE005,E042"
 
 [testenv:docs]
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 whitelist_externals = bash
 setenv =
@@ -44,7 +42,6 @@ commands =
   sphinx-build -W -b html -d doc/build/doctrees doc/source doc/build/html
 
 [testenv:pdf-docs]
-basepython = python3
 deps = {[testenv:docs]deps}
 whitelist_externals =
    make
@@ -53,6 +50,5 @@ commands =
    make -C doc/build/pdf
 
 [testenv:venv]
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = {posargs}