Cleanup py27 support

- 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
- Update requirements
- Remove wheel and setup-hooks from setup.cfg

Change-Id: Id4817c9b25e77000acdebe2a116a32b77b33d24a

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = http://www.openstack.org/
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -13,10 +14,11 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
-    Programming Language :: Python :: 2
+    Programming Language :: Python :: Implementation :: CPython
-    Programming Language :: Python :: 2.7
+    Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.5
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
 
 keywords =
     setup
@@ -30,19 +32,7 @@ packages =
 tempest.test_plugins =
     cyborg_tempest_plugin = cyborg_tempest_plugin.plugin:CyborgTempestPlugin
 
-[global]
-setup-hooks =
-    pbr.hooks.setup_hook
-
-[build_sphinx]
-all_files = 1
-build-dir = doc/build
-source-dir = doc/source
-
 [egg_info]
 tag_build =
 tag_date = 0
 tag_svn_revision = 0
-
-[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'],
     pbr=True)

test-requirements.txt

@@ -9,7 +9,7 @@ python-subunit>=0.0.18 # Apache-2.0/BSD
 oslotest>=1.10.0 # Apache-2.0
 stestr>=1.0.0 # Apache-2.0
 testtools>=1.4.0 # MIT
-sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
+sphinx>=1.8.0,!=2.1.0 # BSD
 openstackdocstheme>=1.18.1 # Apache-2.0
 # releasenotes
 reno>=2.5.0 # Apache-2.0