Merge pull request #13 from germanattanasio/greenkeeper-mocha-3.1.0

Update mocha to version 3.1.0 🚀

package.json

@@ -18,7 +18,7 @@
     "url": "https://github.com/germanattanasio/vcap_services/issues"
   },
   "devDependencies": {
-    "mocha": "~3.0.0",
+    "mocha": "~3.1.0",
     "coveralls": "~2.11.2",
     "istanbul": "~0.4.0",
     "jshint": "~2.9.1"