Add Python 3 Train unit tests

This is a mechanically generated patch to ensure unit testing is in place
for all of the Tested Runtimes for Train.

See the Train python3-updates goal document for details:
https://governance.openstack.org/tc/goals/train/python3-updates.html

Co-Authored-By: gujin <gu.jin@99cloud.net>
Change-Id: Ib98f78131050be2c38a0128d2e2a792639c03c1c
Story: #2005924
Task: #34221

.zuul.yaml

@@ -84,14 +84,13 @@
       - openstack-cover-jobs
       - openstack-lower-constraints-jobs
       - openstack-python-jobs
-      - openstack-python35-jobs
+      - openstack-python3-train-jobs
-      - openstack-python36-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check:
       jobs:
         - masakari-functional-devstack-multinode:
-            voting: True
+            voting: true
 
 - project:
     masakari-systemfault-integration-ci:

setup.cfg

@@ -16,7 +16,8 @@ classifier =
     Programming Language :: Python :: 2
     Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.5
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
 
 [files]
 data_files =

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 2.0
-envlist = pep8,py27,py35,py36
+envlist = pep8,py27,py36,py37
 skipsdist = True
 
 [testenv]
@@ -27,14 +27,14 @@ commands =
     {[testenv]commands}
     stestr run {posargs}
 
-[testenv:py35]
+[testenv:py36]
-basepython = python3
+basepython = python3.6
 commands =
     {[testenv]commands}
     stestr run {posargs}
 
-[testenv:py36]
+[testenv:py37]
-basepython = python3.6
+basepython = python3.7
 commands =
     {[testenv]commands}
     stestr run {posargs}