Add ARA artifact

The ara-report role used to add this but it hasn't been updated for
the latest ARA (I008b35562994f1205a4f66e53f93b9885a6b8754).  Add it
back here.

Change-Id: I2d56e7cde32cd7adabb359a35ecdaa9f0880f7d5

playbooks/zuul/run-base-post.yaml

@@ -63,6 +63,14 @@
       become: yes
       ignore_errors: true
 
+    - name: Add ARA artifact
+      zuul_return:
+        data:
+          zuul:
+            artifacts:
+              - name: ARA report
+                url: "bridge.openstack.org/ara-report/"
+
     - name: Collect ansible configuration
       synchronize:
         dest: "{{ log_dir }}/etc"