Upgrade to react-scripts 3.0.1

See https://github.com/facebook/create-react-app/blob/master/CHANGELOG.md#301-2019-05-08

Author: shakuzen

package.json

@@ -26,7 +26,7 @@
     "jquery": "^3.3.1",
     "loader-utils": "^1.2.3",
     "popper.js": "^1.14.7",
-    "react-scripts": "2.1.8"
+    "react-scripts": "3.0.1"
   },
   "scripts": {
     "start": "react-scripts start",