Add ESM test command to CI workflow

Author: bourgeoa

.github/workflows/ci.yml

@@ -54,6 +54,7 @@ jobs:
     - run: npm run standard
     - run: npm run validate
     - run: npm run nyc
+    - run: npm run test-esm
     # Test global install of the package
     - run: npm pack .
     - run: npm install -g solid-server-*.tgz