Update to ELK 6.6.1 (#368)

.env

-ELK_VERSION=6.6.0
+ELK_VERSION=6.6.1

README.md

 # Elastic stack (ELK) on Docker
 
 [![Join the chat at https://gitter.im/deviantony/docker-elk](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/deviantony/docker-elk?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Elastic Stack version](https://img.shields.io/badge/ELK-6.6.0-blue.svg?style=flat)](https://github.com/deviantony/docker-elk/issues/362)
+[![Elastic Stack version](https://img.shields.io/badge/ELK-6.6.1-blue.svg?style=flat)](https://github.com/deviantony/docker-elk/issues/367)
 [![Build Status](https://api.travis-ci.org/deviantony/docker-elk.svg?branch=master)](https://travis-ci.org/deviantony/docker-elk)
 
 Run the latest version of the [Elastic stack](https://www.elastic.co/elk-stack) with Docker and Docker Compose.
@@ -127,7 +127,7 @@ Create an index pattern via the Kibana API:
 ```console
 $ curl -XPOST -D- 'http://localhost:5601/api/saved_objects/index-pattern' \
     -H 'Content-Type: application/json' \
-    -H 'kbn-version: 6.6.0' \
+    -H 'kbn-version: 6.6.1' \
     -d '{"attributes":{"title":"logstash-*","timeFieldName":"@timestamp"}}'
 ```
 

docker-stack.yml

@@ -3,7 +3,7 @@ version: '3.3'
 services:
 
   elasticsearch:
-    image: docker.elastic.co/elasticsearch/elasticsearch-oss:6.6.0
+    image: docker.elastic.co/elasticsearch/elasticsearch-oss:6.6.1
     ports:
       - "9200:9200"
       - "9300:9300"
@@ -19,7 +19,7 @@ services:
       replicas: 1
 
   logstash:
-    image: docker.elastic.co/logstash/logstash-oss:6.6.0
+    image: docker.elastic.co/logstash/logstash-oss:6.6.1
     ports:
       - "5000:5000"
       - "9600:9600"
@@ -37,7 +37,7 @@ services:
       replicas: 1
 
   kibana:
-    image: docker.elastic.co/kibana/kibana-oss:6.6.0
+    image: docker.elastic.co/kibana/kibana-oss:6.6.1
     ports:
       - "5601:5601"
     configs: