Update .gitlab-ci.yml

.gitlab-ci.yml

@@ -3,7 +3,7 @@
 image: docker:stable
 variables:
   IMAGE: $CI_REGISTRY_IMAGE
-  DOCKER_HOST: tcp://localhost:2375/
+  DOCKER_HOST: tcp://docker:2375/
   DOCKER_DRIVER: overlay2
 stages:
   - build
@@ -11,7 +11,8 @@ stages:
   - push
 
 services:
-- docker:dind
+- name: docker:dind
+  alias: docker
 
 Build docker image:
   stage: build