chore(package): update utf-8-validate to version 4.0.0 (#1247)

Author: greenkeeper[bot]

package.json

@@ -41,6 +41,6 @@
     "eslint-plugin-standard": "~3.0.0",
     "mocha": "~4.0.0",
     "nyc": "~11.3.0",
-    "utf-8-validate": "~3.0.0"
+    "utf-8-validate": "~4.0.0"
   }
 }