fix(package): update react-scripts to version 3.1.1

Closes #12

Author: greenkeeper[bot]

example/package.json

@@ -9,7 +9,7 @@
     "prop-types": "^15.6.2",
     "react": "^16.4.1",
     "react-dom": "^16.4.1",
-    "react-scripts": "^2.1.5",
+    "react-scripts": "^3.1.1",
     "react-with-firebase-auth": "file:..",
     "recompose": "^0.30.0"
   },