fix(package): update react-scripts to version 3.4.0

Closes #21

Author: greenkeeper[bot]

package.json

@@ -7,7 +7,7 @@
     "react": "^16.6.3",
     "react-dom": "^16.6.3",
     "react-router-dom": "^4.3.1",
-    "react-scripts": "3.1.0",
+    "react-scripts": "3.4.0",
     "recompose": "^0.30.0"
   },
   "scripts": {