Add ansible functional tests on stable-2.6

Ansible uses openstacksdk as of 2.6, so we should also run tests against
the stable-2.6 branch.

Change-Id: I260b9f0b7acbda3a6c9fccc1bef27906c1f298b4

.zuul.yaml

@@ -208,6 +208,15 @@
     vars:
       tox_envlist: ansible
 
+- job:
+    name: openstacksdk-ansible-functional-devstack
+    parent: openstacksdk-functional-devstack
+    description: |
+      Run openstacksdk ansible functional tests against a master devstack
+      using released version of ansible.
+    vars:
+      tox_envlist: ansible
+
 - job:
     name: openstacksdk-ansible-devel-functional-devstack
     parent: openstacksdk-ansible-functional-devstack
@@ -229,6 +238,27 @@
       test_matrix_branch: master
       tox_install_siblings: true
 
+- job:
+    name: openstacksdk-ansible-stable-2.6-functional-devstack
+    parent: openstacksdk-ansible-functional-devstack
+    description: |
+      Run openstacksdk ansible functional tests against a master devstack
+      using git stable-2.6 branch version of ansible.
+    branches: ^(stable-2.6|master)$
+    required-projects:
+      - name: github.com/ansible/ansible
+        override-checkout: stable-2.6
+      - name: openstack/openstacksdk
+        override-checkout: master
+      - name: openstack-dev/devstack
+        override-checkout: master
+    vars:
+      # test-matrix grabs branch from the zuul branch setting. If the job
+      # is triggered by ansible, that branch will be devel which doesn't
+      # make sense to devstack. Override so that we run the right thing.
+      test_matrix_branch: master
+      tox_install_siblings: true
+
 - project-template:
     name: openstacksdk-functional-tips
     check:
@@ -256,6 +286,8 @@
               sphinx_python: python3
         - openstacksdk-ansible-devel-functional-devstack:
             voting: false
+        - openstacksdk-ansible-stable-2.6-functional-devstack:
+            voting: false
         - openstacksdk-functional-devstack
         - openstacksdk-functional-devstack-magnum:
             voting: false