chore(package): update babel-jest to version 21.0.0 (#26)

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
   ],
   "license": "MIT",
   "devDependencies": {
-    "babel-jest": "^20.0.0",
+    "babel-jest": "^21.0.0",
     "babel-plugin-external-helpers": "^6.22.0",
     "babel-polyfill": "^6.23.0",
     "babel-preset-es2015": "^6.24.0",