Stop using sebp/elk docker image, use elastic official images instead

[barryib]

Stop using the so famous sebp/elk docker image, but use docker-compose or even systemd to orchestrate elastic official docker images:

• Elasticsearch: https://www.elastic.co/guide/en/elasticsearch/reference/current/docker.html
• Logstash: https://www.elastic.co/guide/en/logstash/current/docker.html
• Kibana: https://www.elastic.co/guide/en/kibana/current/_pulling_the_image.html