Update .gitlab-ci.yml file

.gitlab-ci.yml

 image: node:latest
 
 stages:          # List of stages for jobs, and their order of execution
+  - npm
   - build
   - test
 
+npm:
+  stage: npm
+  script:
+    - npm ci
+  cache:
+    paths:
+      - node_modules/
+
 build-job:       # This job runs in the build stage, which runs first.
   stage: build
   script:
-    - npm ci
+    - npm run build
 
 unit-test-job:   # This job runs in the test stage.
   stage: test    # It only starts when the job in the build stage completes successfully.