Remove recycler and it's usage

- The memory usage due to recycler was high, and incrementing with
  time.

src/lib.rs

@@ -41,7 +41,6 @@ pub mod payment_plan;
 pub mod poh;
 pub mod poh_recorder;
 pub mod recvmmsg;
-pub mod recycler;
 pub mod replicate_stage;
 pub mod replicator;
 pub mod request;