Add minimum rust version

COMPILING.md

@@ -7,8 +7,6 @@ In order to compile librespot, you will first need to set up a suitable Rust bui
 ### Install Rust
 The easiest, and recommended way to get Rust is to use [rustup](https://rustup.rs). Once that’s installed, Rust's standard tools should be set up and ready to use.
 
-*Note: The current minimum supported Rust version at the time of writing is 1.61.*
-
 #### Additional Rust tools - `rustfmt`
 To ensure a consistent codebase, we utilise [`rustfmt`](https://github.com/rust-lang/rustfmt) and [`clippy`](https://github.com/rust-lang/rust-clippy), which are installed by default with `rustup` these days, else they can be installed manually with:
 ```bash

Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Librespot Org"]
 license = "MIT"
 description = "An open source client library for Spotify, with support for Spotify Connect"

audio/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot-audio"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Paul Lietar <paul@lietar.net>"]
 description = "The audio fetching logic for librespot"
 license = "MIT"

connect/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot-connect"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Paul Lietar <paul@lietar.net>"]
 description = "The discovery and Spotify Connect logic for librespot"
 license = "MIT"

core/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot-core"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Paul Lietar <paul@lietar.net>"]
 build = "build.rs"
 description = "The core functionality provided by librespot"

discovery/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot-discovery"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Paul Lietar <paul@lietar.net>"]
 description = "The discovery logic for librespot"
 license = "MIT"

metadata/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot-metadata"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Paul Lietar <paul@lietar.net>"]
 description = "The metadata logic for librespot"
 license = "MIT"

playback/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot-playback"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Sasha Hilton <sashahilton00@gmail.com>"]
 description = "The audio playback logic for librespot"
 license = "MIT"

protocol/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "librespot-protocol"
 version = "0.5.0-dev"
+rust-version = "1.61"
 authors = ["Paul Liétar <paul@lietar.net>"]
 build = "build.rs"
 description = "The protobuf logic for communicating with Spotify servers"