Cleanup py27 support

Make a few cleanups:
- Remove python 2.7 stanza from setup.py
- 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 classifiers
- Update requirements, no need for python_version anymore
- Use sphinx-build everywhere

Change-Id: I737d176d35d3bc55848645af05f0362ab3853844

setup.cfg

@@ -6,13 +6,16 @@ description-file =
 author = OpenStack
 author-email = [email protected]
 home-page = https://docs.openstack.org/virtualbmc/latest/
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
     Intended Audience :: System Administrators
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
+    Programming Language :: Python :: Implementation :: CPython
+    Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
@@ -34,15 +37,6 @@ virtualbmc =
     list = virtualbmc.cmd.vbmc:ListCommand
     show = virtualbmc.cmd.vbmc:ShowCommand
 
-[build_sphinx]
-source-dir = doc/source
-build-dir = doc/build
-all_files = 1
-warning-is-error = 1
-
-[upload_sphinx]
-upload-dir = doc/build/html
-
 [compile_catalog]
 directory = virtualbmc/locale
 domain = virtualbmc

setup.py

@@ -13,17 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
 import setuptools
 
-# In python < 2.7.4, a lazy loading of package `pbr` will break
-# setuptools if some other modules registered functions in `atexit`.
-# solution from: http://bugs.python.org/issue15881#msg170215
-try:
-    import multiprocessing  # noqa
-except ImportError:
-    pass
-
 setuptools.setup(
     setup_requires=['pbr>=2.0.0'],
     pbr=True)

test-requirements.txt

@@ -7,7 +7,7 @@ hacking>=3.0.0,<3.1.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 doc8>=0.6.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD
-sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2;python_version>='3.4' # BSD
+sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2 # BSD
 openstackdocstheme>=1.20.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD

tox.ini

@@ -40,7 +40,7 @@ commands =
   coverage xml -o cover/coverage.xml
 
 [testenv:docs]
-commands = python setup.py build_sphinx
+commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:pdf-docs]
 whitelist_externals = make