Free up the name 'tpu'

src/lib.rs

@@ -18,12 +18,12 @@ pub mod plan;
 pub mod recorder;
 pub mod request_stage;
 pub mod result;
+pub mod rpu;
 pub mod sig_verify_stage;
 pub mod signature;
 pub mod streamer;
 pub mod thin_client;
 pub mod timing;
-pub mod tpu;
 pub mod transaction;
 pub mod tvu;
 extern crate bincode;