Update .gitlab-ci.yml file

.gitlab-ci.yml

+# https://hub.docker.com/r/library/node/tags/
+image: node:latest
+
+stages:
+  - deploy
+
+deploy-job:
+  stage: deploy
+  script:
+    - npm install
+    - npx pm2 start ./index.js --name=energy-dashboard
+  only:
+    - master