fix(package): update @angular/core to version 5.1.0

Closes #116

Author: greenkeeper[bot]

package.json

@@ -15,7 +15,7 @@
   "dependencies": {
     "@angular/common": "^4.1.3",
     "@angular/compiler": "^4.1.3",
-    "@angular/core": "^4.1.3",
+    "@angular/core": "^5.1.0",
     "@angular/forms": "^4.1.3",
     "@angular/http": "^4.1.3",
     "@angular/platform-browser": "^4.1.3",