chore(package): update mocha to version 5.2.0

package.json

@@ -28,7 +28,7 @@
   },
   "devDependencies": {
     "istanbul": "~0.4.5",
-    "mocha": "~5.1.0",
+    "mocha": "~5.2.0",
     "pre-commit": "~1.2.0",
     "webpack": "~4.8.2"
   }