Set docker-compose-tests.yml to use new "tests" aegir image

travis/docker-compose-tests.yml

@@ -3,19 +3,15 @@ version: '2'
 services:
 
   hostmaster:
-    image: aegir/hostmaster
+    image: aegir/hostmaster:test
     ports:
       - 80:80
     hostname: aegir.local.computer
     links:
       - database
     depends_on:
       - database
-    entrypoint:
-    # See https://github.com/aegir-project/dockerfiles/blob/master/docker-entrypoint-tests.sh
-      - docker-entrypoint-tests.sh
     environment:
-      VIRTUAL_HOST: aegir.local.computer
       MYSQL_ROOT_PASSWORD: strongpassword
     tty: true
     stdin_open: true