chore(package): update @nguniversal/express-engine to version 9.1.0

Closes #37

Author: greenkeeper[bot]

demo/package.json

@@ -64,7 +64,7 @@
     "@angular/compiler-cli": "^7.2.11",
     "@angular/language-service": "^7.2.11",
     "@angularclass/hmr": "~2.1.3",
-    "@nguniversal/express-engine": "^7.1.1",
+    "@nguniversal/express-engine": "^9.1.0",
     "@nguniversal/module-map-ngfactory-loader": "^7.1.1",
     "@types/jest": "^24.0.11",
     "@types/node": "^10.14.4",