cleanup some build warnings (#1661)

core/src/pow/cuckatoo.rs

@@ -12,13 +12,12 @@
 // limitations under the License.
 
 //! Implementation of Cuckatoo Cycle designed by John Tromp.
-use pow::num::ToPrimitive;
 use std::mem;
 
-use byteorder::{BigEndian, LittleEndian, WriteBytesExt};
+use byteorder::{BigEndian, WriteBytesExt};
 use croaring::Bitmap;
 
-use pow::common::{self, CuckooParams, EdgeType, Link};
+use pow::common::{CuckooParams, EdgeType, Link};
 use pow::error::{Error, ErrorKind};
 use pow::{PoWContext, Proof};
 use util;

core/src/pow/cuckoo.rs

@@ -17,9 +17,8 @@
 //! simple miner is included, mostly for testing purposes. John Tromp's Tomato
 //! miner will be much faster in almost every environment.
 
-use pow::common::{self, CuckooParams, Edge, EdgeType};
+use pow::common::{CuckooParams, Edge, EdgeType};
 use pow::error::{Error, ErrorKind};
-use pow::num::ToPrimitive;
 use pow::{PoWContext, Proof};
 
 use std::cmp;

core/src/pow/lean.rs

@@ -13,15 +13,12 @@
 
 //! Lean miner for Cuckatoo Cycle
 
-use std::time::{Duration, Instant};
-
 use croaring::Bitmap;
 
 use pow::common::CuckooParams;
 use pow::cuckatoo::CuckatooContext;
-use pow::error::{Error, ErrorKind};
-use pow::siphash::siphash24;
-use pow::{PoWContext, Proof};
+use pow::error::Error;
+use pow::Proof;
 
 /// Lean miner implementation aiming to be as short and simple as possible.
 /// As a consequence, it's a little less than 10 times slower than John

core/src/pow/mod.rs

@@ -47,7 +47,6 @@ mod siphash;
 mod types;
 
 use chrono::prelude::{DateTime, NaiveDateTime, Utc};
-use consensus;
 use core::{Block, BlockHeader};
 use genesis;
 use global;