fix(package.json): 🆙 mocha v2.x -> v3.x

Author: pine

package.json

@@ -26,7 +26,7 @@
     "karma-phantomjs2-launcher": "^0.5.0",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^1.7.0",
-    "mocha": "^2.5.3",
+    "mocha": "^3.0.0",
     "text-encoding": "^0.6.0",
     "webpack": "^1.13.1"
   },