add a DNSSEC-disabled NameServer scenario test

to ensure that hickory-dns is correctly configured to work in NameServer
mode

packages/conformance-tests/src/name_server.rs

@@ -1 +1,2 @@
 mod rfc4035;
+mod scenarios;

packages/conformance-tests/src/name_server/scenarios.rs

@@ -0,0 +1,23 @@
+use dns_test::client::{Client, DigSettings};
+use dns_test::name_server::NameServer;
+use dns_test::record::RecordType;
+use dns_test::{Network, Result, FQDN};
+
+#[test]
+fn authoritative_answer() -> Result<()> {
+    let network = &Network::new()?;
+    let ns = NameServer::new(&dns_test::subject(), FQDN::ROOT, network)?.start()?;
+
+    let client = Client::new(network)?;
+    let ans = client.dig(
+        DigSettings::default(),
+        ns.ipv4_addr(),
+        RecordType::SOA,
+        &FQDN::ROOT,
+    )?;
+
+    assert!(ans.status.is_noerror());
+    assert!(ans.flags.authoritative_answer);
+
+    Ok(())
+}