What makes you think it doesn't work with Rust 2018? The very purpose of the edition system is to allow improving the syntax without splitting the library echosystem. You can call the Rust2015 libraries using Rust2018 syntax and vice versa.
Few updates:
On Windows I can't run an example with an error
error[E0432]: unresolved import `timeout_readwrite::TimeoutReadExt`
--> examples\process.rs:9:5
|
9 | use timeout_readwrite::TimeoutReadExt;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `TimeoutReadExt` in the root
But on Linux it works. On Windows rustc 1.51.0 on linux rustc 1.48.0