chore(package): update @angular/platform-browser to version 5.1.2

Closes #16

Author: greenkeeper[bot]

package.json

@@ -65,7 +65,7 @@
     "@angular/compiler-cli": "^4.0.0",
     "@angular/core": "^4.0.0",
     "@angular/forms": "^4.0.0",
-    "@angular/platform-browser": "^4.0.0",
+    "@angular/platform-browser": "^5.1.2",
     "@angular/platform-browser-dynamic": "^4.0.0",
     "@compodoc/compodoc": "^1.0.0-beta.9",
     "@types/jasmine": "^2.5.47",