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

Closes #29

Author: greenkeeper[bot]

demo/package.json

@@ -47,7 +47,7 @@
     "@angularclass/hmr": "~2.1.3",
     "@compodoc/gulp-compodoc": "0.0.10",
     "@nguniversal/common": "^7.0.2",
-    "@nguniversal/express-engine": "^7.0.2",
+    "@nguniversal/express-engine": "^9.1.0",
     "@nguniversal/module-map-ngfactory-loader": "^7.0.2",
     "@types/jest": "^24.0.13",
     "@types/node": "^11.13.11",