switch to patched rspotify until upstream has merged pr

PR: https://github.com/samrayleung/rspotify/pull/36

Cargo.toml

@@ -17,7 +17,6 @@ crossbeam-channel = "0.3.8"
 failure = "0.1.3"
 futures = "0.1"
 log = "0.4.0"
-rspotify = "0.2.5"
 serde = "1.0"
 serde_json = "1.0"
 toml = "0.4"
@@ -28,6 +27,10 @@ unicode-width = "0.1.5"
 dbus = { version = "0.6.4", optional = true }
 xdg = "^2.1"
 
+[dependencies.rspotify]
+git = "https://github.com/hrkfdn/rspotify.git"
+rev = "6029b8f50f4e5fade2ded3e3fdfe5ab8e3908450"
+
 [dependencies.librespot]
 git = "https://github.com/librespot-org/librespot.git"
 rev = "daeeeaa122fc2d71edf11e562e23038db4210b39"