migrate to rspotify 0.9-dev

in preparation for the future release with podcast API support

src/library.rs

@@ -5,7 +5,7 @@ use std::path::PathBuf;
 use std::sync::{Arc, RwLock, RwLockReadGuard};
 use std::thread;
 
-use rspotify::spotify::model::playlist::SimplifiedPlaylist;
+use rspotify::model::playlist::SimplifiedPlaylist;
 use serde::de::DeserializeOwned;
 use serde::Serialize;