Try MacOS and Windows too

Author: eriknw

.github/workflows/test.yml

@@ -14,8 +14,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: ["ubuntu-latest"] #, "macos-latest", "windows-latest"]
-        python-version: [3.7] #, 3.8, 3.9]
+        os: ["ubuntu-latest", "macos-latest", "windows-latest"]
+        python-version: [3.7, 3.8, 3.9]
     steps:
     - name: Checkout
       uses: actions/checkout@v2