Update rodio to 0.8

[est31]

Note that this is untested because I couldn't find any audio/sound examples. But cargo test still works and it still compiles.

[vitvakatu]

Thank you. I was pretty sure we have example with audio (we even have music.flac in test_data!). Perhaps we can add one.

[est31]

Sure, if you add an example, I'd love to test it.

[bors[bot]]

Build succeeded

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