latest jest (#656)

Author: Ben Hamlin

packages/razzle/package.json

@@ -48,7 +48,7 @@
     "eslint-plugin-react": "^7.3.0",
     "file-loader": "^1.1.11",
     "fs-extra": "3.0.1",
-    "jest": "^22.4.3",
+    "jest": "^23.1.0",
     "mini-css-extract-plugin": "^0.4.0",
     "object-assign": "^4.1.1",
     "postcss-flexbugs-fixes": "3.3.0",