Merge pull request mseemann#4 from mseemann/greenkeeper-zone.js-0.6.23

Update zone.js to version 0.6.23 🚀

Author: mseemann

package.json

@@ -23,7 +23,7 @@
     "core-js": "2.4.1",
     "rxjs": "5.0.0-beta.12",
     "systemjs": "0.19.38",
-    "zone.js": "0.6.22"
+    "zone.js": "0.6.23"
   },
   "devDependencies": {
     "@types/gulp": "3.8.31",