Add elasticsearch,. rabbitmq, PHP 7.2 to M2.3.1

Author: Demoli

.travis.yml

@@ -9,9 +9,12 @@ addons:
     - postfix
     - jq
     - nodejs
+services:
+  - rabbitmq
+  - elasticsearch
 language: php
 php:
-- 7.1
+  - 7.2
 env:
   global:
   - COMPOSER_BIN_DIR=~/bin