try a matrix for rust stable and beta

.github/workflows/ci.yml

@@ -70,33 +70,6 @@ jobs:
           RUST_BACKTRACE: full
         run: cargo build --verbose --no-default-features
 
-  build-beta:
-    name: Build using rust beta on ${{ matrix.os }}
-    timeout-minutes: 30
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        os: [ubuntu-latest, windows-latest, macOS-latest]
-
-    steps:
-      - uses: actions/checkout@v1
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: beta
-          override: true
-      - name: Install LLVM on Windows
-        if: matrix.os == 'windows-latest'
-        run: choco install llvm -y
-      - name: cargo fetch
-        uses: actions-rs/cargo@v1
-        with:
-          command: fetch
-      - name: Build
-        uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --verbose --release
-  
   build:
     name: Build on ${{ matrix.os }}
     timeout-minutes: 30
@@ -104,12 +77,13 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macOS-latest]
+        rust: [stable,beta]
 
     steps:
       - uses: actions/checkout@v1
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: ${{ matrix.rust }}
           override: true
       - name: Install LLVM on Windows
         if: matrix.os == 'windows-latest'