Remove unnecessary imports

zcash_client_backend/build.rs

@@ -1,5 +1,3 @@
-use protobuf_codegen_pure;
-
 fn main() {
     protobuf_codegen_pure::Codegen::new()
         .out_dir("src/proto")

zcash_primitives/src/block.rs

@@ -1,7 +1,6 @@
 //! Structs and methods for handling Zcash block headers.
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
-use hex;
 use sha2::{Digest, Sha256};
 use std::fmt;
 use std::io::{self, Read, Write};

zcash_primitives/src/merkle_tree.rs

@@ -505,7 +505,6 @@ mod tests {
     use super::{CommitmentTree, Hashable, IncrementalWitness, MerklePath, PathFiller};
     use crate::sapling::Node;
 
-    use hex;
     use std::convert::TryInto;
     use std::io::{self, Read, Write};
 

zcash_primitives/src/transaction/mod.rs

@@ -1,7 +1,6 @@
 //! Structs and methods for handling Zcash transactions.
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
-use hex;
 use sha2::{Digest, Sha256};
 use std::fmt;
 use std::io::{self, Read, Write};