Presenting upgrade_levels option

Change-Id: Iaf4d329bc141a5c34ea13f358780318510ce1be1
diff --git a/tests/pillar/compute_cluster.sls b/tests/pillar/compute_cluster.sls
index c3a2485..58f98ef 100644
--- a/tests/pillar/compute_cluster.sls
+++ b/tests/pillar/compute_cluster.sls
@@ -66,3 +66,5 @@
         port: 11211
     libvirt:
       hw_disk_discard: unmap
+    upgrade_levels:
+      compute: liberty