Update .gitlab-ci.yml file

.gitlab-ci.yml

 image: alpine:latest
 
+stages:
+    - deploy
+  
+pages:
+  stage: deploy
+  script:
+    - echo "deploy to https://transfer.hft-stuttgart.de/pages/$CI_PROJECT_PATH/"
+  artifacts:
+    paths:
+      - public
+  only: 
+    - master
+
 stages:
     - test
     - deploy