Cleanup py27 support

Make a few cleanups:
- Remove python 2.7 stanza from setup.py
- 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: I79cf58adf35726999a0791525dd28a7e70de4591

setup.cfg

@@ -14,6 +14,8 @@ classifier =
     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
@@ -25,10 +27,6 @@ data_files =
     etc/neutron/rootwrap.d =
         etc/neutron/rootwrap.d/vpnaas.filters
 
-[global]
-setup-hooks =
-    pbr.hooks.setup_hook
-
 [entry_points]
 console_scripts =
     neutron-vpn-netns-wrapper = neutron_vpnaas.services.vpn.common.netns_wrapper:main
@@ -49,11 +47,6 @@ oslo.policy.policies =
 neutron.policies =
     neutron-vpnaas = neutron_vpnaas.policies:list_rules
 
-[build_sphinx]
-all_files = 1
-build-dir = doc/build
-source-dir = doc/source
-
 [extract_messages]
 keywords = _ gettext ngettext l_ lazy_gettext
 mapping_file = babel.cfg
@@ -67,9 +60,3 @@ domain = neutron_vpnaas
 domain = neutron_vpnaas
 output_dir = neutron_vpnaas/locale
 input_file = neutron_vpnaas/locale/neutron_vpnaas.pot
-
-[wheel]
-universal = 1
-
-[pbr]
-warnerrors = true

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

@@ -9,7 +9,7 @@ flake8-import-order==0.12 # LGPLv3
 mock>=2.0.0 # BSD
 pylint==2.3.0 # GPLv2
 requests-mock>=1.2.0 # Apache-2.0
-sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
+sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
 openstackdocstheme>=1.18.1 # Apache-2.0
 tempest>=17.1.0 # Apache-2.0
 testtools>=2.2.0 # MIT