[MM-36445] Changing elastic search docker version (#18117)

* changing elastic docker version for testing

* fixing elastic issue

* temp dockerfile

* test

* removing command

* fixing dockerfile

* adding 7.0.0

* using elasticsearch 7

Co-authored-by: Benjamin Cooke <benjamincooke@Benjamins-MacBook-Pro.local>

build/docker-compose.common.yml

@@ -84,7 +84,7 @@ services:
       LDAP_DOMAIN: "mm.test.com"
       LDAP_ADMIN_PASSWORD: "mostest"
   elasticsearch:
-    image: "mattermost/mattermost-elasticsearch-docker:6.5.1"
+    image: "mattermost/mattermost-elasticsearch-docker:7.0.0"
     networks:
       - mm-test
     environment: