Update .gitlab-ci.yml

.gitlab-ci.yml

@@ -18,15 +18,28 @@ install_dependencies:
   script:
     - yarn install 
 
-build_code:
+.build_job:
   stage: build
-  environment: $CI_COMMIT_BRANCH
+  image: node:12
   script:
-    - yarn run build
+    - echo "build"
+    - yarn build
   artifacts:
-    name: "${CI_COMMIT_SHA}_build"
-    untracked: true
     paths:
       - build/
-    expire_in: 3 hrs
+    untracked: false
+    expire_in: 30 days
+
+build_1:
+  extends: .build_job
+
+build_2:
+  extends: .build_job
+
+build_3:
+  extends: .build_job
+
+build_4:
+  extends: .build_job
+