Codespaces: `composer server start` produces error message

Running `composer server start` under codespaces generates the following error message

```
Missing hosts entries for: s3-localhost., s3-console-localhost., cognito-localhost., pinpoint-localhost., elasticsearch-localhost.
Add the following line to your /etc/hosts file:

127.0.0.1 localhost. s3-localhost. s3-console-localhost. cognito-localhost. pinpoint-localhost. elasticsearch-localhost. # altis:localhost.
```

These local host names may need to be fixed for a Codespaces environment. In particular, `s3-console-localhost` is used by `Tools > S3 Browser` in the Dashboard.

This may need mapping to a different url or port number so the functionality continues to work.

I don't know the purpose of the other host names. If they are not required, they should be removed so the error message is not generated.

Acceptance criteria:

- [ ] No error message is generated