move dind out of default

.gitlab-ci.yml

 default:
-  image: docker:latest
-  services:
-    - docker:dind
   before_script:
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
   interruptible: true
@@ -25,6 +22,9 @@ get-credentials:
 
 docker-build:
   stage: build
+  image: docker:latest
+  services:
+    - docker:dind
   dependencies: 
     - get-credentials
   script: