feat: codecov integration

.github/workflows/test.yml

@@ -11,12 +11,22 @@ jobs:
             uses: actions/setup-python@v5
             with:
               python-version: ${{ matrix.python-version }}
+              cache: 'pip'
           - uses: actions/checkout@v4
           - name: Install dependencies
             run: pip install -r requirements.txt
+          - name: Install CodeCov dependencies
+            run: pip install pytest pytest-cov
           - name: Install self
             run: pip install -e .
           - name: Run tests
             run: |
               cd tests
-              python -m unittest discover
+              pytest --cov --cov-report=xml
+          - name: Upload coverage to Codecov
+            uses: codecov/codecov-action@v2
+            with:
+              token: ${{ secrets.CODECOV_TOKEN }}
+              file: ./tests/coverage.xml
+              flags: unittests
+              fail_ci_if_error: false