Fix gitlab ci build

.gitlab-ci.yml

 docker-build:
   image: docker:latest
   stage: build
+  before_script:
+    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
   # Default branch leaves tag empty (= latest tag)
   # All other branches are tagged with the escaped branch name (commit ref slug)
   script:
@@ -19,6 +21,8 @@ docker-build:
     - if: $CI_COMMIT_BRANCH
       exists:
         - Dockerfile
+  tags:
+    - ecomobicoin
 pages-staging:
   image: alpine:latest
   stage: deploy