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:
  * Wheel is not needed for python 3 only repo
  * Some other sections are obsolete
- Update classifiers
- Update requirements, no need for python_version anymore

Change-Id: I3fdbf332d03794bbec91c6e0ff23296e6f4d711c

doc/requirements.txt

@@ -4,7 +4,6 @@
 openstackdocstheme>=1.20.0 # Apache-2.0
 os-api-ref>=1.4.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
-sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # 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
 sphinxcontrib-httpdomain>=1.3.0 # BSD
 whereto>=0.3.0 # Apache-2.0

setup.cfg

@@ -3,8 +3,11 @@ name = sahara-plugin-mapr
 summary = Mapr Plugin for Sahara Project
 description-file = README.rst
 license = Apache Software License
+python-requires = >=3.6
 classifiers =
     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
@@ -17,9 +20,6 @@ author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/sahara/latest/
 
-[global]
-setup-hooks = pbr.hooks.setup_hook
-
 [files]
 packages =
     sahara_plugin_mapr
@@ -28,12 +28,6 @@ packages =
 sahara.cluster.plugins =
     mapr    = sahara_plugin_mapr.plugins.mapr.plugin:MapRPlugin
 
-[build_sphinx]
-all_files = 1
-build-dir = doc/build
-source-dir = doc/source
-warning-is-error = 1
-
 [compile_catalog]
 directory = sahara_plugin_mapr/locale
 domain = sahara_plugin_mapr
@@ -48,5 +42,3 @@ keywords = _ gettext ngettext l_ lazy_gettext
 mapping_file = babel.cfg
 output_file = sahara_plugin_mapr/locale/sahara_plugin_mapr.pot
 
-[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)