Update .gitlab-ci.yml

.gitlab-ci.yml

-image: alpine:latest
-
-pages:
-  stage: deploy
-  script:
-  - echo 'Nothing to do...'
-  artifacts:
-    paths:
-    - public
-  only:
-  - master
-  tags:
-  - pages
-
+# The Docker image that will be used to build your app
+image: node:its
+# Functions that should be executed before the build script is run
+before_script:
+  - npm ci