chore(package): update nyc to version 12.0.2 (#1395)

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
     "eslint-plugin-promise": "~3.8.0",
     "eslint-plugin-standard": "~3.0.0",
     "mocha": "~5.2.0",
-    "nyc": "~11.8.0",
+    "nyc": "~12.0.2",
     "utf-8-validate": "~4.0.0"
   }
 }