chore(package): update mocha to version 5.0.0

Closes #40

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "jsx-chai": "^4.0.0",
     "mime": "^1.3.4",
     "mkdirp": "^0.5.1",
-    "mocha": "^3.2.0",
+    "mocha": "^5.0.0",
     "mocha-clean": "^1.0.0",
     "react-addons-test-utils": "^15.4.1",
     "react-hot-loader": "^1.3.0",