Surface the spy node's id, useful for log analysis

bench-tps/src/main.rs

@@ -36,6 +36,7 @@ fn converge(
 ) -> (Vec<NodeInfo>, Option<NodeInfo>, GossipService) {
     //lets spy on the network
     let (node, gossip_socket) = ClusterInfo::spy_node();
+    println!("Spy node: {}", node.id);
     let mut spy_cluster_info = ClusterInfo::new(node);
     spy_cluster_info.insert_info(leader.clone());
     spy_cluster_info.set_leader(leader.id);