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
- Update classifiers
- Update requirements, no need for python_version anymore

Change-Id: I12ecea6b3cfcca8edd5adedac91f906d77f4ff36

doc/requirements.txt

@@ -1,8 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-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,>=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
 reno>=2.5.0 # Apache-2.0
 sphinxcontrib-apidoc>=0.2.0  # BSD

lower-constraints.txt

@@ -12,7 +12,6 @@ doc8==0.6.0
 docutils==0.14
 dulwich==0.19.0
 enum-compat==0.0.2
-enum34==1.0.4;python_version=='2.7' or python_version=='2.6' or python_version=='3.3' # BSD
 eventlet==0.18.2
 extras==1.0.0
 fasteners==0.14.1

requirements.txt

@@ -7,7 +7,6 @@ oslo.serialization!=2.19.1,>=2.18.0 # Apache-2.0
 oslo.utils>=3.33.0 # Apache-2.0
 oslo.concurrency>=3.26.0 # Apache-2.0
 stevedore>=1.20.0 # Apache-2.0
-enum34>=1.0.4;python_version=='2.7' or python_version=='2.6' or python_version=='3.3' # BSD
 eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT
 six>=1.10.0 # MIT
 

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/glance_store/latest/
+python-requires = >=3.6
 classifier =
     Development Status :: 5 - Production/Stable
     Environment :: OpenStack
@@ -14,6 +15,8 @@ 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
@@ -79,6 +82,3 @@ input_file = glance_store/locale/glance_store.pot
 keywords = _ gettext ngettext l_ lazy_gettext
 mapping_file = babel.cfg
 output_file = glance_store/locale/glance_store.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)