update ci

.github/workflows/macos.yml

@@ -0,0 +1,27 @@
+name: macos
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ${{matrix.config.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+        - { os: macos-10.15, xcode: "12.0.1" } # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md#xcode
+        - { os: macos-11.0, xcode: "11.7" }    # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11.0-Readme.md#xcode
+        build: [Debug, Release]
+
+    name: "xcode${{matrix.config.xcode}}:${{matrix.build}}"
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Configure CMake
+      run: cmake -DCMAKE_BUILD_TYPE=${{matrix.build}}
+
+    - name: Build
+      run: cmake --build . --config ${{matrix.build}}
+
+    - name: Tests
+      run: ctest --output-on-failure -C ${{matrix.build}}