End-to-end unit test (#90)

* First implementation of create_torrent_file

* Test harness for e2e preparing

* Saving

* Continuing test harness

* Continuing test harness

* Continuing test harness

* All servers are running

* Full e2e harness done

* Test e2e harness working fine

* Remove lints

* injecting faults

* The e2e test runs continuously

* e2e test

* Add a test for create_torrent

* Nothing

* Nothing, just tweaking the numberes

* Update tokio, remove custom tempfile shim

crates/librqbit/src/session.rs

@@ -1136,6 +1136,10 @@ impl Session {
         handle.start(peer_rx, false, self.cancellation_token.child_token())?;
         Ok(())
     }
+
+    pub fn tcp_listen_port(&self) -> Option<u16> {
+        self.tcp_listen_port
+    }
 }
 
 // Ad adapter for converting stats into the format that tracker_comms accepts.