aiosmtpd CLI Authentication

I'm trying to set up a basic mail server to test an application with e-mail reporting. It will only stay on localhost, but I do need authentication and StartTLS. I've gotten StartTLS support working with the aiosmptd CLI, but I can't get the AUTH command to work.

aiosmtpd command line:

```
aiosmtpd -n -l :8001 --tlscert cert.crt --tlskey key.key
```

Connection command line:

```
$ openssl s_client -starttls smtp -connect localhost:8001 -quiet -crlf

ehlo example.com
250-[hostname]
250-8BITMIME
250-AUTH LOGIN PLAIN
250 HELP
auth login
504 5.5.4 Unrecognized authentication type
```

I've looked at the docs and it says that Auth is implemented but rejects all by default. How can I turn it on from the CLI?