Set zone.js to 0.8.12

see: angular/zone.js#832

Author: bertdireins

package.json

@@ -23,7 +23,7 @@
     "@angular/router": "^4.0.0",
     "core-js": "^2.4.1",
     "rxjs": "^5.1.0",
-    "zone.js": "^0.8.4"
+    "zone.js": "0.8.12"
   },
   "devDependencies": {
     "@angular/cli": "1.2.0",