chore(package): update mocha to version 5.2.0 (#1385)

package.json

@@ -37,7 +37,7 @@
     "eslint-plugin-node": "~6.0.0",
     "eslint-plugin-promise": "~3.7.0",
     "eslint-plugin-standard": "~3.0.0",
-    "mocha": "~5.1.0",
+    "mocha": "~5.2.0",
     "nyc": "~11.8.0",
     "utf-8-validate": "~4.0.0"
   }