Add a comment to state why TestConn2 is interesting.

client_test.go

@@ -104,6 +104,7 @@ func TestConn(t *testing.T) {
 	}
 }
 
+// ftp.mozilla.org uses multiline 220 response
 func TestConn2(t *testing.T) {
 	c, err := Connect("ftp.mozilla.org:21")
 	if err != nil {
@@ -119,4 +120,6 @@ func TestConn2(t *testing.T) {
 	if err != nil {
 		t.Error(err)
 	}
+
+	c.Quit()
 }