properly checkout repo, use tox

.github/workflows/test_wheels.yml

@@ -16,8 +16,17 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
-      - name: Install wheel
-        run: |
-          pip install -U pip wheel
-          pip install -i https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple pyfolio-reloaded[test]
-          pytest tests
+      - name: Checkout pyfolio
+        uses: actions/checkout@v4
+
+      - name: Unittests with tox & pytest
+        uses: nick-fields/retry@v3
+        with:
+          timeout_minutes: 90
+          max_attempts: 3
+          retry_on: error
+          new_command_on_retry: |
+            python -m pip install -U pip wheel tox tox-gh-actions
+            python -m pip install -i https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple pyfolio-reloaded[test]
+            tox
+          command: tox -p auto -q