Zuul: add file extension to playbook path

Zuul now supports including the file extension on the playbook path
and omitting the extension is now deprecrated.  Update references
to include the extension.

Change-Id: I3af2e786ac17b039147de3560aa2fa8cee4c83cd

.zuul.yaml

@@ -3,9 +3,9 @@
     parent: legacy-dsvm-base
     timeout: 7800
     nodeset: legacy-ubuntu-xenial
-    pre-run: playbooks/pre/prepare-workspace
-    run: playbooks/magnum-functional-base
-    post-run: playbooks/post/upload-logs
+    pre-run: playbooks/pre/prepare-workspace.yaml
+    run: playbooks/magnum-functional-base.yaml
+    post-run: playbooks/post/upload-logs.yaml
     required-projects:
       - openstack-infra/devstack-gate
       - openstack/diskimage-builder
@@ -31,16 +31,16 @@
       multinode: 0
       neutron: 1
       tempest: 0
-      branch_override: "default"
+      branch_override: default
 
 - job:
     name: magnum-functional-multinode-base
     parent: legacy-dsvm-base-multinode
     timeout: 7800
     nodeset: legacy-ubuntu-xenial-2-node
-    pre-run: playbooks/pre/prepare-workspace
-    run: playbooks/magnum-functional-base
-    post-run: playbooks/post/upload-logs
+    pre-run: playbooks/pre/prepare-workspace.yaml
+    run: playbooks/magnum-functional-base.yaml
+    post-run: playbooks/post/upload-logs.yaml
     required-projects:
       - openstack-infra/devstack-gate
       - openstack/diskimage-builder
@@ -66,20 +66,20 @@
       multinode: 1
       neutron: 1
       tempest: 0
-      branch_override: "default"
+      branch_override: default
 
 - job:
     name: magnum-functional-api
     parent: magnum-functional-base
     vars:
-      coe: "api"
+      coe: api
 
 - job:
     name: magnum-functional-k8s
     parent: magnum-functional-base
     voting: false
     vars:
-      coe: "k8s"
+      coe: k8s
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*$
@@ -95,7 +95,7 @@
     voting: false
     branches: ^(?!stable/(newton|ocata)).*$
     vars:
-      coe: "swarm-mode"
+      coe: swarm-mode
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*$
@@ -112,7 +112,7 @@
     voting: false
     branches: ^(?!stable/(newton|ocata)).*$
     vars:
-      coe: "dcos"
+      coe: dcos
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*$
@@ -128,7 +128,7 @@
     parent: magnum-functional-base
     voting: false
     vars:
-      coe: "mesos"
+      coe: mesos
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*$
@@ -143,7 +143,7 @@
     parent: magnum-functional-base
     voting: false
     vars:
-      coe: "swarm"
+      coe: swarm
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*$
@@ -159,7 +159,7 @@
     parent: magnum-functional-base
     voting: false
     vars:
-      coe: "k8s"
+      coe: k8s
       ironic: 1
     irrelevant-files:
       - ^.*\.rst$
@@ -175,7 +175,7 @@
     parent: magnum-functional-base
     voting: false
     vars:
-      coe: "swarm"
+      coe: swarm
       ironic: 1
     irrelevant-files:
       - ^.*\.rst$
@@ -191,7 +191,7 @@
     parent: magnum-functional-multinode-base
     voting: false
     vars:
-      coe: "k8s"
+      coe: k8s
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*$
@@ -207,7 +207,7 @@
     voting: false
     branches: ^(?!stable/(newton|ocata)).*$
     vars:
-      coe: "swarm-mode"
+      coe: swarm-mode
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*$
@@ -221,8 +221,8 @@
 - job:
     name: magnum-non-functional-tox-migration
     nodeset: legacy-ubuntu-xenial
-    run: playbooks/magnum-tox-migration
-    post-run: playbooks/post/upload-logs-tox
+    run: playbooks/magnum-tox-migration.yaml
+    post-run: playbooks/post/upload-logs-tox.yaml
     timeout: 2400
     required-projects:
       - openstack/requirements
@@ -232,9 +232,9 @@
     parent: legacy-publish-openstack-artifacts
     timeout: 3600
     nodeset: legacy-ubuntu-xenial
-    pre-run: playbooks/pre/prepare-workspace-images
-    run: playbooks/magnum-buildimages-base
-    post-run: playbooks/post/upload-images
+    pre-run: playbooks/pre/prepare-workspace-images.yaml
+    run: playbooks/magnum-buildimages-base.yaml
+    post-run: playbooks/post/upload-images.yaml
     required-projects:
       - openstack/dib-utils
       - openstack/diskimage-builder
@@ -244,19 +244,19 @@
     name: magnum-dib-buildimage-fedora-atomic-25
     parent: magnum-buildimages-base
     vars:
-      image_name: "fedora-atomic-25"
+      image_name: fedora-atomic-25
 
 - job:
     name: magnum-dib-buildimage-ubuntu-mesos
     parent: magnum-buildimages-base
     vars:
-      image_name: "ubuntu-mesos"
+      image_name: ubuntu-mesos
 
 - job:
     name: magnum-dib-buildimage-centos-dcos
     parent: magnum-buildimages-base
     vars:
-      image_name: "centos-dcos"
+      image_name: centos-dcos
 
 - project:
     name: openstack/magnum