update to Rust 1.60 as minimal version

Cargo.toml

@@ -9,7 +9,7 @@ readme = "README.md"
 categories = ["command-line-utilities", "development-tools::build-utils"]
 keywords = ["ccache"]
 edition = "2018"
-rust-version = "1.58"
+rust-version = "1.60"
 
 [[bin]]
 name = "sccache"

README.md

@@ -137,7 +137,7 @@ By default, sccache will fail your build if it fails to successfully communicate
 Build Requirements
 ------------------
 
-sccache is a [Rust](https://www.rust-lang.org/) program. Building it requires `cargo` (and thus `rustc`). sccache currently requires **Rust 1.58.0**. We recommend you install Rust via [Rustup](https://rustup.rs/).
+sccache is a [Rust](https://www.rust-lang.org/) program. Building it requires `cargo` (and thus `rustc`). sccache currently requires **Rust 1.60.0**. We recommend you install Rust via [Rustup](https://rustup.rs/).
 
 Build
 -----

tests/test-crate/Cargo.lock

@@ -1,16 +1,16 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "itoa"
 version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8324a32baf01e2ae060e9de58ed0bc2320c9a2833491ee36cd3b4c414de4db8c"
 
 [[package]]
 name = "test-crate"
 version = "0.1.0"
 dependencies = [
- "itoa 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "itoa",
 ]
-
-[metadata]
-"checksum itoa 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8324a32baf01e2ae060e9de58ed0bc2320c9a2833491ee36cd3b4c414de4db8c"