fix(package): update react-scripts to version 2.1.2

Closes #3

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": "^1.1.4"
+    "react-scripts": "^2.1.2"
   },
   "scripts": {
     "start": "react-scripts start",