Release 5.5.1

Closes #158

README.md

 # Docker ELK stack
 
-[![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-5.5.0-blue.svg?style=flat)](https://github.com/deviantony/docker-elk/issues/146)
+[![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-5.5.1-blue.svg?style=flat)](https://github.com/deviantony/docker-elk/issues/158)
 
 Run the latest version of the ELK (Elasticsearch, Logstash, Kibana) stack with Docker and Docker Compose.
 
@@ -127,7 +127,7 @@ $ curl -XPUT -D- 'http://localhost:9200/.kibana/index-pattern/logstash-*' \
 This command will mark the Logstash index pattern as the default index pattern:
 
 ```bash
-$ curl -XPUT -D- 'http://localhost:9200/.kibana/config/5.5.0' \
+$ curl -XPUT -D- 'http://localhost:9200/.kibana/config/5.5.1' \
     -H 'Content-Type: application/json' \
     -u kibana:changeme \
     -d '{"defaultIndex": "logstash-*"}'

elasticsearch/Dockerfile

 # https://github.com/elastic/elasticsearch-docker
-FROM docker.elastic.co/elasticsearch/elasticsearch:5.5.0
+FROM docker.elastic.co/elasticsearch/elasticsearch:5.5.1
 
 # Add your elasticsearch plugins setup here
 # Example: RUN elasticsearch-plugin install analysis-icu

kibana/Dockerfile

 # https://github.com/elastic/kibana-docker
-FROM docker.elastic.co/kibana/kibana:5.5.0
+FROM docker.elastic.co/kibana/kibana:5.5.1
 
 # Add your kibana plugins setup here
 # Example: RUN kibana-plugin install <name|url>

logstash/Dockerfile

 # https://github.com/elastic/logstash-docker
-FROM docker.elastic.co/logstash/logstash:5.5.0
+FROM docker.elastic.co/logstash/logstash:5.5.1
 
 # Add your logstash plugins setup here
 # Example: RUN logstash-plugin install logstash-filter-json