Use cargo resolver 2

This is required for "cargo build --lib" to not activate
Tokio features from dev-dependencies. Otherwise, the
build fails on WebAssembly.

Author: surban

Cargo.toml

@@ -3,6 +3,7 @@ name = "async-compression"
 version = "0.4.18"
 authors = ["Wim Looman <[email protected]>", "Allen Bui <[email protected]>"]
 edition = "2018"
+resolver = "2"
 license = "MIT OR Apache-2.0"
 keywords = ["compression", "gzip", "zstd", "brotli", "async"]
 categories = ["compression", "asynchronous"]