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

Closes #102

Author: greenkeeper[bot]

demo/package.json

@@ -59,7 +59,7 @@
     "@angular/language-service": "^7.2.0",
     "@angularclass/hmr": "~2.1.3",
     "@nguniversal/common": "^7.0.0",
-    "@nguniversal/express-engine": "^7.0.0",
+    "@nguniversal/express-engine": "^9.1.0",
     "@nguniversal/module-map-ngfactory-loader": "^7.0.0",
     "@types/jest": "^23.3.12",
     "@types/node": "^6.14.2",