chore(package): update jest to version 21.2.1

Closes #45

Author: greenkeeper[bot]

package.json

@@ -114,7 +114,7 @@
     "happypack": "4.0.0-beta.3",
     "html-webpack-plugin": "2.30.1",
     "husky": "0.14.3",
-    "jest": "21.0.0",
+    "jest": "21.2.1",
     "lint-staged": "4.0.4",
     "md5": "2.2.1",
     "node-notifier": "5.1.2",