[ussuri][goal] Updates for python 2.7 drop

OpenStack is dropping the py2.7 support in ussuri cycle except
swift and sorlets which is exception approved in this goal.

Somehow this repo is left to remove the support of py2.7.

Ussuri Communtiy-wide goal:
https://governance.openstack.org/tc/goals/selected/ussuri/drop-py27.html

Change-Id: Ic9eaaca9981aec50ef1f235d69a03ad2698e36fe

.zuul.yaml

@@ -1,7 +1,6 @@
 - project:
     templates:
       - openstack-python3-ussuri-jobs
-      - openstack-python3-train-jobs
       - check-requirements
     gate:
       queue: tripleo

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/tripleo-docs/latest/
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -13,8 +14,8 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
-    Programming Language :: Python :: 2
-    Programming Language :: Python :: 2.7
+    Programming Language :: Python :: Implementation :: CPython
+    Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
@@ -23,15 +24,6 @@ classifier =
 packages =
     tripleo_common_tempest_plugin
 
-[build_sphinx]
-all_files = 1
-warning-is-error = 1
-source-dir = doc/source
-build-dir = doc/build
-
-[upload_sphinx]
-upload-dir = doc/build/html
-
 [compile_catalog]
 directory = tripleo_common_tempest_plugin/locale
 domain = tripleo_common_tempest_plugin

test-requirements.txt

@@ -11,8 +11,7 @@ testrepository>=0.0.18 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
 
 # Documentation
-sphinx>=1.8.0,<2.0.0;python_version=='2.7' # BSD
-sphinx>=1.8.0,!=2.1.0;python_version>='3.4' # BSD
+sphinx>=1.8.0,!=2.1.0 # BSD
 reno>=2.5.0 # Apache-2.0
 
 # Bandit build requirements

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 2.0
-envlist = py27,py37,pep8
+envlist = py37,pep8
 skipsdist = True
 
 [testenv]