Add a possibility to deploy Elasticsearch 5.x version

Elasticsearch 2.x version is deployed by default

Change-Id: I78e714807cf5925a9619961ab145f27ef0210652
diff --git a/tests/pillar/cluster.sls b/tests/pillar/cluster.sls
index 316438e..18a0194 100644
--- a/tests/pillar/cluster.sls
+++ b/tests/pillar/cluster.sls
@@ -15,4 +15,5 @@
           port: 9300
     index:
       shards: 5
-      replicas: 1
\ No newline at end of file
+      replicas: 1
+    version: 2
\ No newline at end of file