chore(package): Update mocha to the latest version 🚀 (#481)

Author: greenkeeper[bot]

package-lock.json

@@ -68,7 +68,7 @@
     "iconv-lite": "^0.4.23",
     "istanbul": "^0.4.5",
     "jschardet": "^1.6.0",
-    "mocha": "^5.2.0",
+    "mocha": "^6.0.0",
     "prettier": "^1.15.3",
     "prettylint": "^1.0.0",
     "remap-istanbul": "^0.13.0",