Run unit tests with Python 3.8

Change-Id: I08cee2a5d671fa9302b067f6466dfedfccdba8f6

playbooks/tobiko-tox-py38-pre-run.yaml

@@ -0,0 +1,11 @@
+---
+
+- hosts: all
+  roles:
+    - role: ../roles/python
+      vars:
+        python_version: "3.8"
+        python_release: "3.8.0"
+        pip_install_packages:
+          - virtualenv
+          - tox

zuul.d/project.yaml

@@ -16,6 +16,7 @@
 
     check:
       jobs:
+        - tobiko-tox-py38
         - tobiko-devstack-functional
         - tobiko-devstack-scenario
         - tobiko-devstack-faults-centos-7
@@ -23,6 +24,10 @@
         - tobiko-devstack-faults-centos-7-train
         - tobiko-devstack-faults-ubuntu-bionic
 
+    gate:
+      jobs:
+        - tobiko-tox-py38
+
     experimental:
       jobs:
         - tobiko-devstack-ovn-functional

zuul.d/unit.yaml

@@ -0,0 +1,16 @@
+---
+
+- job:
+    name: tobiko-tox-py38
+    parent: openstack-tox
+    nodeset: centos-7
+    timeout: 2400
+    description: |
+      Run unit tests for an OpenStack Python project under cPython
+      version 3.8.
+      Uses tox with the ``py38`` environment.
+    vars:
+      tox_envlist: py38
+      bindep_profile: test py38
+      python_version: 3.8
+    pre-run: playbooks/tobiko-tox-py38-pre-run.yaml