chore(package): update @nguniversal/express-engine to version 9.1.1

Closes #53

Author: greenkeeper[bot]

demo/package.json

@@ -57,7 +57,7 @@
     "@angularclass/hmr": "~2.1.3",
     "@compodoc/gulp-compodoc": "^0.0.9",
     "@nguniversal/common": "^7.1.1",
-    "@nguniversal/express-engine": "^7.1.1",
+    "@nguniversal/express-engine": "^9.1.1",
     "@nguniversal/module-map-ngfactory-loader": "^7.1.1",
     "@types/jest": "^23.3.14",
     "@types/node": "~10.9.4",