fix: explicitly add react-app-polyfill to package.json

Author: epicfaace

package.json

@@ -48,6 +48,7 @@
  "core-js": "^2.5.7",
  "lodash": "^4.17.15",
  "prop-types": "^15.7.2",
+ "react-app-polyfill": "^1.0.4",
  "react-is": "^16.9.0",
  "shortid": "^2.2.14"
  },