Update .gitlab-ci.yml

.gitlab-ci.yml

 #image: python:alpine
 image: centos:latest
 
+## integrate k8s cluster
+deploy to staging:
+#  stage: deploy
+  script: make deploy
+  environment:
+    name: staging/$CI_COMMIT_REF_NAME
+    url: https://staging.example.com/
+
+## push code on VM
 deploy_prod:
   #script: git push production HEAD:master
   script:
@@ -16,7 +25,7 @@ deploy_prod:
 #   - pip install mkdocs
   # Add your custom theme if not inside a theme_dir
   # (https://github.com/mkdocs/mkdocs/wiki/MkDocs-Themes)
-  # - pip install mkdocs-material
+  # - pip install mkdocs-toto
 
 #pages:
 #  stage: deploy