Depends on old version of crossbeam-channel

[RalfJung]

I am working on enabling Rust to better detect misuse of uninitialized memory (rust-lang/rust#71274), and this crate was flagged as a possible regression. Most likely this is because it depends on an old version of crossbeam-channel; there have been many bugfixes there over the last 2 years. Would be great if you could update to a newer version. :)

[workingjubilee]

Thanks for updating in 6977abb @ggriffiniii!

This can be closed.