ci: use artifacts instead of cache for lib

Fixes #23

.gitlab-ci.yml

@@ -3,7 +3,6 @@ image: registry.gitlab.com/openstapps/projectmanagement/node
 cache:
   key: ${CI_COMMIT_REF_SLUG}
   paths:
-    - lib
     - node_modules
 
 before_script:
@@ -18,6 +17,10 @@ build:
   stage: build
   script:
     - npm run build
+  artifacts:
+    paths:
+      - lib
+    expire_in: 1 week
 
 audit:
   stage: test