Bump dbus from 0.8.4 to 0.9.0 (#296)

* Bump dbus from 0.8.4 to 0.9.0

Bumps [dbus](https://github.com/diwic/dbus-rs) from 0.8.4 to 0.9.0.
- [Release notes](https://github.com/diwic/dbus-rs/releases)
- [Commits](https://github.com/diwic/dbus-rs/compare/dbus-v0.8.4...dbus-v0.9.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

* migrate to dbus/dbus-tree 0.9.0

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
Co-authored-by: Henrik Friedrichsen <henrik@affekt.org>

Cargo.toml

@@ -36,7 +36,8 @@ toml = "0.5"
 tokio-core = "0.1"
 tokio-timer = "0.2"
 unicode-width = "0.1.8"
-dbus = { version = "0.8.4", optional = true }
+dbus = { version = "0.9.0", optional = true }
+dbus-tree = { version = "0.9.0", optional = true }
 rand = "0.7"
 webbrowser = "0.5"
 clipboard = { version = "0.5", optional = true }
@@ -57,6 +58,6 @@ pulseaudio_backend = ["librespot-playback/pulseaudio-backend"]
 rodio_backend = ["librespot-playback/rodio-backend"]
 portaudio_backend = ["librespot-playback/portaudio-backend"]
 termion_backend = ["cursive/termion-backend"]
-mpris = ["dbus"]
+mpris = ["dbus", "dbus-tree"]
 notify = ["notify-rust"]
 default = ["share_clipboard", "pulseaudio_backend", "mpris", "notify", "cursive/pancurses-backend"]