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

Closes #2

Author: greenkeeper[bot]

package.json

@@ -5,7 +5,7 @@
   "dependencies": {
     "react": "^16.12.0",
     "react-dom": "^16.12.0",
-    "react-scripts": "3.3.0",
+    "react-scripts": "3.4.0",
     "styled-components": "^4.4.1"
   },
   "scripts": {