chore: Update to 2021 edition (#1188)

tonic-types/Cargo.toml

@@ -5,7 +5,7 @@ description = """
 A collection of useful protobuf types that can be used with `tonic`.
 """
 documentation = "https://docs.rs/tonic-types/0.5.0/tonic-types/"
-edition = "2018"
+edition = "2021"
 homepage = "https://github.com/hyperium/tonic"
 keywords = ["rpc", "grpc", "protobuf"]
 license = "MIT"

tonic-types/src/richer_error/std_messages/retry_info.rs

@@ -1,4 +1,4 @@
-use std::{convert::TryFrom, time};
+use std::time;
 
 use prost::{DecodeError, Message};
 use prost_types::Any;