Fix tox

Author: rhpvorderman

.github/workflows/ci.yml

@@ -94,7 +94,7 @@ jobs:
         uses: ilammy/[email protected]
         if: runner.os == 'Windows'
       - name: Run tests
-        run: tox -e py3
+        run: tox
       - name: Upload coverage report
         uses: codecov/codecov-action@v1