gate: Add centos8/py36 experimental jobs

Change-Id: I47a88afe9f71bce783cf8bd05d4cb7495decadf6

.zuul.yaml

@@ -50,6 +50,11 @@
         NOSE_COVER_HTML_DIR: '{toxinidir}/cover'
     post-run: tools/playbooks/common/cover-post.yaml
 
+- job:
+    name: swift-tox-py36-centos-8
+    parent: swift-tox-py36
+    nodeset: centos-8
+
 - job:
     name: swift-tox-py37
     parent: swift-tox-base
@@ -115,6 +120,26 @@
       bindep_profile: test py37
       python_version: 3.7
 
+- job:
+    name: swift-tox-func-py36-centos-8
+    parent: swift-tox-func-py37
+    nodeset: centos-8
+    vars:
+      bindep_profile: test py36
+      python_version: 3.6
+
+- job:
+    name: swift-tox-func-encryption-py36-centos-8
+    parent: swift-tox-func-py36-centos-8
+    vars:
+      tox_envlist: func-encryption-py3
+
+- job:
+    name: swift-tox-func-ec-py36-centos-8
+    parent: swift-tox-func-py36-centos-8
+    vars:
+      tox_envlist: func-ec-py3
+
 - job:
     name: swift-tox-func-encryption-py37
     parent: swift-tox-func-py37
@@ -656,6 +681,10 @@
         - swift-tox-func-py27-centos-7
         - swift-tox-func-encryption-py27-centos-7
         - swift-tox-func-ec-py27-centos-7
+        - swift-tox-py36-centos-8
+        - swift-tox-func-py36-centos-8
+        - swift-tox-func-encryption-py36-centos-8
+        - swift-tox-func-ec-py36-centos-8
         - swift-multinode-rolling-upgrade-rocky
         - swift-multinode-rolling-upgrade-stein
         - swift-multinode-rolling-upgrade-train