chore(package): update jest to version 22.1.4

Closes #25

Author: greenkeeper[bot]

package.json

@@ -73,7 +73,7 @@
     "babel-runtime": "^6.11.6",
     "coveralls": "^3.0.0",
     "cross-env": "^5.0.0",
-    "jest": "^21.0.0",
+    "jest": "^22.1.4",
     "nodemon": "^1.9.0",
     "npm-run-all": "^4.0.1",
     "onchange": "^3.0.2",