Cleanup py27 support

This repo is now testing only with Python 3, so let's make
a few cleanups:
- Remove python 2.7 stanza from setup.py
- Remove obsolete sections from setup.cfg

Change-Id: I26ecb693ca3ac35ec3195cac2d1ae9de3fd1b122

setup.cfg

@@ -11,14 +11,3 @@ classifier =
     Intended Audience :: System Administrators
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
-
-[build_sphinx]
-all_files = 1
-build-dir = doc/build
-source-dir = doc/source
-
-[pbr]
-warnerrors = True
-
-[wheel]
-universal = 1

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)

tox.ini

@@ -36,7 +36,7 @@ setenv =
 deps = -r{toxinidir}/doc/requirements.txt
 commands =
     bash -c "rm -rf doc/build"
-    sphinx-build --keep-going -b html doc/source doc/build/html
+    sphinx-build -W --keep-going -b html doc/source doc/build/html
 
 [testenv:pdf-docs]
 deps = {[testenv:docs]deps}