Upgrade jest for gluestick generated apps

Author: christinebrass

packages/gluestick/package.json

@@ -90,7 +90,7 @@
     "http-proxy-middleware": "0.17.4",
     "ignore-loader": "0.1.2",
     "inquirer": "3.2.0",
-    "jest": "20.0.4",
+    "jest": "23.4.2",
     "lru-cache": "4.1.1",
     "mkdirp": "0.5.1",
     "node-fetch": "^1.7.1",