ci: test windows

Author: william-silversmith

.github/workflows/python-package.yml

@@ -23,10 +23,20 @@ jobs:
       uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
-    - name: Install dependencies
+
+    - name: Install dependencies (Linux/macOS)
+      if: runner.os != 'Windows'
       run: |
         python -m pip install --upgrade pip
         if [ -f requirements.txt ]; then pip install -r requirements.txt -r requirements_dev.txt; fi
+
+    - name: Install dependencies (Windows)
+      if: runner.os == 'Windows'
+      run: |
+        python -m pip install --upgrade pip
+        if (Test-Path requirements.txt) { pip install -r requirements.txt -r requirements_dev.txt }
+      shell: pwsh
+      
     - name: Test with pytest
       run: |
         python -m pytest -v -x test