Update .gitlab-ci.yml

.gitlab-ci.yml

+before_script:
+  - npm install
+
 cache:
   paths:
   - node_modules/
 
 stages:
+  - build
   - test
+  - deploy
+
+build:
+  stage: build
+  script:
+    - npm build
 
-test:
-  stage: test
+deploy_code:
+  stage: deploy
+  only:
+    - master
   script:
-   - npm install
-   - node index.js
-  tags:
-   - local-tag
+    - echo 'command deploy here.'
+
+after_script:
+    - echo 'after script here.'