Merge branch 'master' into 0.5.1-tests

eth2/utils/boolean-bitfield/src/lib.rs

@@ -9,7 +9,6 @@ use serde_hex::{encode, PrefixedHexVisitor};
 use ssz::{Decodable, Encodable};
 use std::cmp;
 use std::default;
-use tree_hash::tree_hash_ssz_encoding_as_list;
 
 /// A BooleanBitfield represents a set of booleans compactly stored as a vector of bits.
 /// The BooleanBitfield is given a fixed size during construction. Reads outside of the current size return an out-of-bounds error. Writes outside of the current size expand the size of the set.

eth2/utils/ssz_derive/src/lib.rs

@@ -38,7 +38,7 @@
 extern crate proc_macro;
 
 use proc_macro::TokenStream;
-use quote::{quote, ToTokens};
+use quote::quote;
 use syn::{parse_macro_input, DeriveInput};
 
 /// Returns a Vec of `syn::Ident` for each named field in the struct.