Add Elasticsearch 6 support

Remove predefined version from formula
Start using states instead of modules in client.sls
Update test repos to mirror.mirantis.com
Update tests to use ES6
Disable all x-pack features

Change-Id: I7f5a65b0777f2ebce9bd3aae79888d2b00d428b6
Prod-Related: PROD-25122
diff --git a/tests/pillar/cluster.sls b/tests/pillar/cluster.sls
index 18a0194..1972b40 100644
--- a/tests/pillar/cluster.sls
+++ b/tests/pillar/cluster.sls
@@ -16,4 +16,4 @@
     index:
       shards: 5
       replicas: 1
-    version: 2
\ No newline at end of file
+    version: 5