Change python3.5 job to python3.7 job on Stein+

python3.5 was the only supported python3 version on Xenial, now that we have
Bionic Beaver nodes that support python3.7, lets switch to testing with
python3.7 in addition with python3.6 in Stein and beyond.
See ML discussion here [1] for context. [

[1] http://lists.openstack.org/pipermail/openstack-dev/2018-October/135632.html

Change-Id: Ibafa5cc1be81a897a11f01c3df26c644852a45c9
Signed-off-by: Charles Short <chucks@redhat.com>

.zuul.yaml

@@ -12,10 +12,10 @@
       - openstack/os-client-config
 
 - job:
-    name: os-client-config-tox-py35-tips
-    parent: openstack-tox-py35
+    name: os-client-config-tox-py37-tips
+    parent: openstack-tox-py37
     description: |
-      Run tox python 35 unittests against master of important libs
+      Run tox python 37 unittests against master of important libs
     vars:
       tox_install_siblings: true
       zuul_work_dir: src/git.openstack.org/openstack/os-client-config
@@ -29,11 +29,11 @@
     check:
       jobs:
         - os-client-config-tox-py27-tips
-        - os-client-config-tox-py35-tips
+        - os-client-config-tox-py37-tips
     gate:
       jobs:
         - os-client-config-tox-py27-tips
-        - os-client-config-tox-py35-tips
+        - os-client-config-tox-py37-tips
 
 - project:
     templates:
@@ -43,8 +43,8 @@
       - check-requirements
       - publish-openstack-docs-pti
       - openstack-python-jobs
-      - openstack-python35-jobs
       - openstack-python36-jobs
+      - openstack-python37-jobs
       - lib-forward-testing
       - lib-forward-testing-python3
       - release-notes-jobs-python3

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = py35,py27,pep8
+envlist = py37,py27,pep8
 skipsdist = True
 
 [testenv]