Role integration-tests : use a group match for openafs

This adds a group match for the openafs hosts.  This is so a further
role can run kafs separately.

Change-Id: I5ade7a4c34c89f79012fbcd85efcefddb9c0e810

.zuul.yaml

@@ -296,6 +296,9 @@
         - name: puppet3
           nodes:
             - base
+        - name: openafs
+          nodes:
+            - base
 
 - job:
     name: system-config-zuul-role-integration-bionic
@@ -308,6 +311,9 @@
         - name: puppet5
           nodes:
             - base
+        - name: openafs
+          nodes:
+            - base
 
 - job:
     name: system-config-zuul-role-integration-debian-stable
@@ -316,6 +322,10 @@
       nodes:
         - name: base
           label: debian-stretch
+      groups:
+        - name: openafs
+          nodes:
+            - base
 
 - project-template:
     name: system-config-zuul-role-integration

roles-test/openafs-client.yaml

@@ -1,5 +1,5 @@
 - name: Kerberos and OpenAFS client installation
-  hosts: base
+  hosts: openafs
   roles:
     - role: kerberos-client
       kerberos_realm: 'OPENSTACK.ORG'