roll back create-react-app

due to bug with coverage - facebook/create-react-app#8689

Author: penx

package.json

@@ -8,7 +8,7 @@
     "@testing-library/user-event": "^7.1.2",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
-    "react-scripts": "3.4.1"
+    "react-scripts": "3.4.0"
   },
   "scripts": {
     "start": "react-scripts -r @cypress/instrument-cra start",