Drop python3.6/3.7 support in testing runtime

In Zed cycle testing runtime, we are targetting to drop the
python 3.6/3.7 support, project started adding python 3.8 as minimum,

example nova:
- 56b5aed08c/setup.cfg (L13)

Also indicates that we support python 3.9.

Change-Id: I9f9e63fcea02a90a08bfb381755ed76cdd35ddef

.zuul.yaml

@@ -9,43 +9,43 @@
     check:
       jobs:
         - tooz-tox-py38-etcd
-        - tooz-tox-py36-etcd
+        - tooz-tox-py39-etcd
         - tooz-tox-py38-etcd3gw
-        - tooz-tox-py36-etcd3gw
+        - tooz-tox-py39-etcd3gw
         - tooz-tox-py38-zookeeper
-        - tooz-tox-py36-zookeeper
+        - tooz-tox-py39-zookeeper
         - tooz-tox-py38-redis
-        - tooz-tox-py36-redis
+        - tooz-tox-py39-redis
         - tooz-tox-py38-sentinel
-        - tooz-tox-py36-sentinel
+        - tooz-tox-py39-sentinel
         - tooz-tox-py38-memcached
-        - tooz-tox-py36-memcached
+        - tooz-tox-py39-memcached
         - tooz-tox-py38-postgresql
-        - tooz-tox-py36-postgresql
+        - tooz-tox-py39-postgresql
         - tooz-tox-py38-mysql
-        - tooz-tox-py36-mysql
+        - tooz-tox-py39-mysql
         - tooz-tox-py38-consul
-        - tooz-tox-py36-consul
+        - tooz-tox-py39-consul
     gate:
       jobs:
         - tooz-tox-py38-etcd
-        - tooz-tox-py36-etcd
+        - tooz-tox-py39-etcd
         - tooz-tox-py38-etcd3gw
-        - tooz-tox-py36-etcd3gw
+        - tooz-tox-py39-etcd3gw
         - tooz-tox-py38-zookeeper
-        - tooz-tox-py36-zookeeper
+        - tooz-tox-py39-zookeeper
         - tooz-tox-py38-redis
-        - tooz-tox-py36-redis
+        - tooz-tox-py39-redis
         - tooz-tox-py38-sentinel
-        - tooz-tox-py36-sentinel
+        - tooz-tox-py39-sentinel
         - tooz-tox-py38-memcached
-        - tooz-tox-py36-memcached
+        - tooz-tox-py39-memcached
         - tooz-tox-py38-postgresql
-        - tooz-tox-py36-postgresql
+        - tooz-tox-py39-postgresql
         - tooz-tox-py38-mysql
-        - tooz-tox-py36-mysql
+        - tooz-tox-py39-mysql
         - tooz-tox-py38-consul
-        - tooz-tox-py36-consul
+        - tooz-tox-py39-consul
 
 - job:
     name: tooz-tox-py38-consul
@@ -124,77 +124,77 @@
       tox_envlist: py38-zookeeper
 
 - job:
-    name: tooz-tox-py36-consul
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-consul
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-consul`` environment.
+      Run tests using ``py39-consul`` environment.
     vars:
-      tox_envlist: py36-consul
+      tox_envlist: py39-consul
 
 - job:
-    name: tooz-tox-py36-etcd
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-etcd
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-etcd`` environment.
+      Run tests using ``py39-etcd`` environment.
     vars:
-      tox_envlist: py36-etcd
+      tox_envlist: py39-etcd
 
 - job:
-    name: tooz-tox-py36-etcd3gw
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-etcd3gw
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-etcd3gw`` environment.
+      Run tests using ``py39-etcd3gw`` environment.
     vars:
-      tox_envlist: py36-etcd3gw
+      tox_envlist: py39-etcd3gw
 
 - job:
-    name: tooz-tox-py36-memcached
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-memcached
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-memcached`` environment.
+      Run tests using ``py39-memcached`` environment.
     vars:
-      tox_envlist: py36-memcached
+      tox_envlist: py39-memcached
 
 - job:
-    name: tooz-tox-py36-mysql
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-mysql
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-mysql`` environment.
+      Run tests using ``py39-mysql`` environment.
     vars:
-      tox_envlist: py36-mysql
+      tox_envlist: py39-mysql
 
 - job:
-    name: tooz-tox-py36-postgresql
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-postgresql
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-postgresql`` environment.
+      Run tests using ``py39-postgresql`` environment.
     vars:
-      tox_envlist: py36-postgresql
+      tox_envlist: py39-postgresql
 
 - job:
-    name: tooz-tox-py36-redis
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-redis
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-redis`` environment.
+      Run tests using ``py39-redis`` environment.
     vars:
-      tox_envlist: py36-redis
+      tox_envlist: py39-redis
     pre-run:
       - playbooks/stop-redis.yaml
 
 - job:
-    name: tooz-tox-py36-sentinel
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-sentinel
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-sentinel`` environment.
+      Run tests using ``py39-sentinel`` environment.
     vars:
-      tox_envlist: py36-sentinel
+      tox_envlist: py39-sentinel
     pre-run:
       - playbooks/stop-redis.yaml
 
 - job:
-    name: tooz-tox-py36-zookeeper
-    parent: openstack-tox-py36
+    name: tooz-tox-py39-zookeeper
+    parent: openstack-tox-py39
     description: |
-      Run tests using ``py36-zookeeper`` environment.
+      Run tests using ``py39-zookeeper`` environment.
     vars:
-      tox_envlist: py36-zookeeper
+      tox_envlist: py39-zookeeper

setup.cfg

@@ -6,7 +6,7 @@ summary = Coordination library for distributed systems.
 description_file = README.rst
 license = Apache-2
 home_page = https://docs.openstack.org/tooz/latest/
-python_requires = >=3.6
+python_requires = >=3.8
 classifier =
     Environment :: OpenStack
     Intended Audience :: Developers
@@ -15,9 +15,8 @@ classifier =
     Operating System :: POSIX :: Linux
     Programming Language :: Python
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.6
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: Implementation :: CPython
     Topic :: System :: Distributed Computing