chore(package): update jest to version 21.0.1

Closes #15

Author: greenkeeper[bot]

package.json

@@ -44,7 +44,7 @@
     "eslint-plugin-promise": "^3.5.0",
     "eslint-plugin-react": "^7.1.0",
     "eslint-plugin-standard": "^3.0.1",
-    "jest": "^20.0.4",
+    "jest": "^21.0.1",
     "jest-cli": "^20.0.4",
     "react-addons-test-utils": "^15.6.0",
     "readline-sync": "^1.4.7",