ci: update OS versions to 'latest' and switch to dtolnay

Author: BurntSushi

.github/workflows/ci.yml

@@ -23,56 +23,51 @@ jobs:
         - win-gnu
         include:
         - build: pinned
-          os: ubuntu-18.04
+          os: ubuntu-latest
           rust: 1.34.0
         - build: pinned-win
-          os: windows-2019
+          os: windows-latest
           rust: 1.34.0
         - build: stable
-          os: ubuntu-18.04
+          os: ubuntu-latest
           rust: stable
         - build: beta
-          os: ubuntu-18.04
+          os: ubuntu-latest
           rust: beta
         - build: nightly
-          os: ubuntu-18.04
+          os: ubuntu-latest
           rust: nightly
         - build: macos
           os: macos-latest
           rust: stable
         - build: win-msvc
-          os: windows-2019
+          os: windows-latest
           rust: stable
         - build: win-gnu
-          os: windows-2019
+          os: windows-latest
           rust: stable-x86_64-gnu
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v1
-      with:
-        fetch-depth: 1
+      uses: actions/checkout@v3
     - name: Install Rust
-      uses: hecrj/setup-rust-action@v1
+      uses: dtolnay/rust-toolchain@master
       with:
-        rust-version: ${{ matrix.rust }}
+        toolchain: ${{ matrix.rust }}
     - run: cargo build --verbose
     - run: cargo doc --verbose
     - run: cargo test --verbose
 
   rustfmt:
     name: rustfmt
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v1
-      with:
-        fetch-depth: 1
+      uses: actions/checkout@v3
     - name: Install Rust
-      uses: hecrj/setup-rust-action@v1
+      uses: dtolnay/rust-toolchain@master
       with:
-        rust-version: stable
-    - name: Install rustfmt
-      run: rustup component add rustfmt
+        toolchain: stable
+        components: rustfmt
     - name: Check formatting
       run: |
         cargo fmt --all -- --check