Automatically set SELinux

Fixes SELinux issues. Docker-Compose can do this on the fly https://github.com/docker/compose/issues/643

docker-compose.yml

@@ -13,8 +13,8 @@ services:
     networks:
         - docker_elk
 #    volumes:
-#      - my-path:/var/ossec/data
-#      - my-path:/etc/postfix
+#      - my-path:/var/ossec/data:Z
+#      - my-path:/etc/postfix:Z
     depends_on:
       - elasticsearch
   logstash:
@@ -23,7 +23,7 @@ services:
     restart: always
     command: -f /etc/logstash/conf.d/
 #    volumes:
-#      - my-path:/etc/logstash/conf.d
+#      - my-path:/etc/logstash/conf.d:Z
     links:
      - kibana
      - elasticsearch:elasticsearch
@@ -60,7 +60,7 @@ services:
         hard: -1
     mem_limit: 2g
 #    volumes:
-#      - my-path:/usr/share/elasticsearch/data
+#      - my-path:/usr/share/elasticsearch/data:Z
     networks:
         - docker_elk
   kibana: