TEST: add license checker

npm-packages/license_checker.yml

+before_script:
+  - npm install -g js-green-licenses
+ 
+cache:
+      paths:
+        - node_modules/
+ 
+license_check:
+    stage: license-check
+    tags:
+      - docker
+    image: node:latest
+    script:
+      - npm install
+      - jsgl --local ./ || exit 1
+    only:
+      - tags