Run CI on other operating systems (#91)

* Run CI on other operating systems

* Don't run twice in pull requests

* Windows is too slow

.github/workflows/ci.yml

@@ -1,14 +1,22 @@
 name: CI
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - main
+  pull_request:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
       - name: Install alsa and udev
         run: sudo apt-get update; sudo apt-get install --no-install-recommends libasound2-dev libudev-dev
+        if: runner.os == 'Linux'
       - name: check
         run: cargo check
       - name: examples