Load test builds in expo

Have expo project, want public testing URL

The expo has restricted loading of apps from the public for ios, but here's a workaround that we use to let users test our apps when we do rapid-prototyping...

1. create a GitHub action to build the expo app with a unique app name for each PR, so you don't accidentally do anything to your production app and so comments are stamped to specific feature branches
2. run npx expo publish --non-interactive
3. look for the output URL which looks like this:
   image: /uploads/ 📝 Manifest: https://exp.host/@***/***-pr-40/index.exp?sdkVersion=40.0.0 Learn more: https://expo.fyi/manifest-url
4. Copy that URL into a QR code generator like this one:
   http://goqr.me/#t=url
   Or use a CLI script to do it at the end of the build process:
   https://www.npmjs.com/package/qrcode
   And then email it to the users that you want to test!
5. Scan the code on your iPhone!