message: remove unused `use` in the cardano-c binding lib
diff: -use cardano::hdwallet;
  use cardano::fee::{self, LinearFee};
  use cardano::coin::Coin;
  use cardano::config::ProtocolMagic;
  @@ -7,10 +6,8 @@ use cardano::txbuild::{TxBuilder, TxFinalized};
  use cardano::tx::{self, TxInWitness, TxId};
  use cardano::txutils::OutputPolicy;
  use std::{
  - ffi,
  ptr,
  slice,
  - os::raw::{c_char, c_int},
  };
  use types::*;
  