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 section from setup.cfg: Wheel is not needed for python
  3 only repo
- Remove html_last_updated_fmt from source/conf.py, this is not
  needed anymore.

Change-Id: If9708106263493396693771e9bd5265e26de460c

doc/source/conf.py

@@ -48,7 +48,6 @@ apidoc_separate_modules = True
 repository_name = 'openstack/python-troveclient'
 bug_project = 'python-troveclient'
 bug_tag = ''
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
 html_theme = 'openstackdocs'
 
 templates_path = ['_templates']

releasenotes/source/conf.py

@@ -39,7 +39,6 @@ extensions = [
 repository_name = 'openstack/python-troveclient'
 bug_project = 'python-troveclient'
 bug_tag = ''
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/python-troveclient/latest
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -101,7 +102,3 @@ openstack.database.v1 =
     datastore_version_list = troveclient.osc.v1.datastores:ListDatastoreVersions
     datastore_version_show = troveclient.osc.v1.datastores:ShowDatastoreVersion
     datastore_version_delete = troveclient.osc.v1.datastores:DeleteDatastoreVersion
-
-
-[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)