chore(package): update utf-8-validate to version 2.0.0 (#927)

https://greenkeeper.io/

package.json

@@ -37,6 +37,6 @@
     "eslint-plugin-standard": "~2.0.1",
     "istanbul": "~0.4.5",
     "mocha": "~3.2.0",
-    "utf-8-validate": "~1.2.1"
+    "utf-8-validate": "~2.0.0"
   }
 }