Add puppet-swift-tripleo-standalone job

* It overrrides the tripleo-standalone featureset override to run
  Object Storage specific tempest tests.
* It will help to detect the puppet-swift tempest specific issues
  early in gates.

Depends-On: https://review.openstack.org/#/c/612245/

Change-Id: If303b5af5cf68781dd42cc7d44e77e10bc77cdf7

.zuul.yaml

@@ -5,5 +5,21 @@
       - puppet-openstack-integration-jobs-scenario002
       - puppet-openstack-beaker-jobs
       - tripleo-puppet-undercloud
-      - tripleo-puppet-standalone
       - release-notes-jobs-python3
+    check:
+      jobs:
+        - puppet-swift-tripleo-standalone
+    gate:
+      jobs:
+        - puppet-swift-tripleo-standalone
+
+- job:
+    name: puppet-swift-tripleo-standalone
+    parent: tripleo-puppet-ci-centos-7-standalone
+    description: |
+      TripleO standalone Job running Object Storage specific Tempest tests.
+    vars:
+      featureset_override:
+        run_tempest: true
+        tempest_whitelist:
+          - 'object_storage'