fix: matrix

Author: conblem

.github/workflows/rust.yaml

@@ -60,12 +60,16 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
           args: --all-features
   coverage:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ macos-latest, windows-latest, ubuntu-latest ],
+        toolchain: [ stable, nightly ]
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: ${{ matrix.toolchain }}
       - uses: actions/cache@v2
         with:
           path: |