upgrade mocha version

src/connector/grafana/tdengine/package.json

@@ -34,12 +34,13 @@
     "grunt-systemjs-builder": "^1.0.0",
     "jsdom": "~9.12.0",
     "load-grunt-tasks": "^3.5.2",
-    "mocha": "^3.2.0",
+    "mocha": "^6.2.2",
     "prunk": "^1.3.0",
     "q": "^1.5.0"
   },
   "dependencies": {
-    "lodash": "^4.17.13"
+    "lodash": "^4.17.13",
+    "yarn": "^1.21.1"
   },
   "homepage": "https://github.com/taosdata/TDengine/tree/develop/src/connector/grafana/tdengine"
 }