Actions: add macos

.github/workflows/build.yml

@@ -78,4 +78,15 @@ jobs:
         with:
           name: ${{ github.job }}
           path: |
-            /home/runner/work/feather/feather/build/release/bin/feather.exe
+            /home/runner/work/feather/feather/build/release/bin/feather.exe
+
+  macos:
+    runs-on: macOS-latest
+    steps:
+      - uses: actions/checkout@v1
+        with:
+          submodules: recursive
+      - name: install dependencies
+        run: HOMEBREW_NO_AUTO_UPDATE=1 brew install qt@5 libsodium libzip qrencode unbound cmake boost hidapi openssl expat libunwind-headers protobuf pkg-config
+      - name: build
+        run: CMAKE_PREFIX_PATH=/opt/homebrew/opt/qt@5/ make mac-release -j3