V2 Cartridge Support

We've recently migrated user cartridges to our new V2 format and there have been some logic changes/updates required in your quickstart.

- Environment variables for host and port are now named for the web cartridge and no longer have `INTERNAL` in their names
- The action_hooks no longer have the cartridge version in them

Please note that we will soon be removing our fork of this quickstart and any future updates or fixes will be made as pull requests against your repository.