chore: update to rust 2021 edition (#70)

* chore: update to rust 2021 edition

Also update the minimum rust version to 1.67.1.

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ on:
     branches: master
 
 env:
-  MSRV: 1.63.0
+  MSRV: 1.67.1
   RUSTFLAGS: "-Dwarnings"
   CARGO_INCREMENTAL: 0
   RUST_BACKTRACE: 1

Cargo.toml

@@ -3,9 +3,9 @@ name = "bls-signatures"
 version = "0.15.0"
 authors = ["dignifiedquire <dignifiedquire@gmail.com>"]
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 resolver = "2"
-rust-version = "1.63.0"
+rust-version = "1.67.1"
 
 description = "Aggregate BLS Signatures"
 documentation = "https://docs.rs/bls-signatures"

rust-toolchain

@@ -1 +1 @@
-1.63.0
+1.67.1

src/key.rs

@@ -245,8 +245,6 @@ fn key_gen<T: AsRef<[u8]>>(data: T) -> Scalar {
 /// https://tools.ietf.org/html/draft-irtf-cfrg-bls-signature-02#section-2.3
 #[cfg(feature = "blst")]
 fn key_gen<T: AsRef<[u8]>>(data: T) -> Scalar {
-    use std::convert::TryInto;
-
     let data = data.as_ref();
     assert!(data.len() >= 32, "IKM must be at least 32 bytes");