elastisearch: assume single node setup

Setup elasticsearch to be single node. This setting will be
templatized later when scalability will be working.

This patch is making status of elasticsearch in sciirus green
for newly created instance.

src/templates/docker-compose.yml.j2

@@ -14,7 +14,7 @@ suricata:
 
 elasticsearch:
     build: $basepath/docker/elasticsearch
-    command: -Des.network.bind_host=0.0.0.0
+    command: -Des.network.bind_host=0.0.0.0 -Des.index.number_of_replicas=0
     volumes:
         - $basepath/elasticsearch:/usr/share/elasticsearch/data:rw