Lock Rodio to v0.9

[andrewburgess]

rodio pushed a change (RustAudio/rodio@0151398) to, updating the dependency cpal to v0.10, which is incompatible with the current librespot implementation.

This wouldn't be noticeable when working with librespot directly based on how Cargo resolves dependencies (I think, still figuring this whole Rust thing out), but if librespot is being used as a dependency in another project, then the newer cpal crate also gets pulled in, and librespot won't compile.

The change in rodio has only occurred in the repository, there hasn't been a new version published, so I figured it would be better to pin the dependency version for the time being.

[willstott101]

I'll have to look properly later, but could we bump cpal? Eventually I think we're going to want to use cpal directly, Rodio is mostly about audio processing, rather than simplifying playback (even though it does happen to provide some extra helpful bits).

[willstott101]

I agree we should pin the version, but it may have to be a revision because there might be unreleased bug fixes too.

[andrewburgess]

That's fair. RustAudio/cpal@51eba20 changed things up a bit so /playback/src/audio_backend/rodio.rs would need to be reworked to deal with the changed definitions

[willstott101]

0.9.0 looks like it'll be fine, I didn't know they'd actually released a new version since RustAudio/rodio#220

LGTM