Merge pull request #7 from donejs/greenkeeper/mocha-4.0.0

Update mocha to the latest version 🚀

Author: matthewp

package.json

@@ -29,7 +29,7 @@
   "devDependencies": {
     "fs-extra": "^2.0.0",
     "jshint": "^2.9.4",
-    "mocha": "^3.2.0",
+    "mocha": "^4.0.0",
     "yeoman-assert": "^3.0.0",
     "yeoman-test": "^1.6.0"
   }