Add support for parsing relay config values

Author: novedevo

sail.conf

@@ -2,4 +2,4 @@ ListenAddress 127.0.0.1
 Port 8000
 Maildir maildir/{destination user:strip and lowercase}/{destination domain:uppercase}
 Hostnames localhost
-Relayables sail_testing@nyble.dev
+Relays nyble.dev

saild/test/integration_tests.py

@@ -6,7 +6,7 @@
 from os import listdir
 
 process: subprocess.Popen[bytes] | None = None
-testfiles = [("happy_path.txt", ["snep", "coati"]), ("abortive.txt", [])]
+testfiles = [("happy_path.txt", ["snep", "coati"]), ("abortive.txt", []), ("relay.txt", [])]
 is_error: bool = True
 
 @dataclass

saild/test/relay.txt

@@ -0,0 +1,15 @@
+S: 220 localhost (Sail) ready
+C: EHLO test.domain
+S: 250-localhost (sail) greets test.domain
+S: 250 Help
+C: MAIL FROM:<[email protected]>
+S: 250 Okay
+C: RCPT TO:<[email protected]>
+S: 250 Okay
+C: DATA
+S: 354 Start mail input
+C: Autogenerated mail from a saild integration test :)
+C: .
+S: 250
+C: QUIT
+S: 221 localhost Goodbye