fix: gitlab ci, tag and stages missing

.gitlab-ci.yml

-
-
+stages:
+  - build
 
 build:
   stage: bundle
   services:
     - docker:18.09.6-dind
+  before_script:
+    - export TAG=${CI_COMMIT_TAG:-latest}
   script:
     - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN registry.e-biz.fr
     - ./build $TAG