try windows tests

Author: nschloe

.github/workflows/ci.yml

@@ -20,9 +20,10 @@ jobs:
         uses: pre-commit/action@v2.0.3
 
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
         python-version: ["3.7", "3.8", "3.9", "3.10"]
     steps:
       - uses: actions/setup-python@v2
@@ -36,4 +37,4 @@ jobs:
           pip install tox
           tox -- --cov tikzplotlib --cov-report xml --cov-report term
       - uses: codecov/codecov-action@v1
-        if: ${{ matrix.python-version == '3.9' }}
+        if: ${{ matrix.python-version == '3.10' && matrix.os == 'ubuntu-latest' }}