use latest rust in macos/windows ci

.github/workflows/macos.yml

@@ -11,6 +11,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+          components: rustfmt, clippy
       - name: Build
         run: cargo build
       - name: Run tests

.github/workflows/windows.yml

@@ -11,6 +11,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+          components: rustfmt, clippy
       - name: Build
         run: cargo build
       - name: Run tests