Setup code coverage

.github/workflows/tests.yml

@@ -6,6 +6,8 @@ jobs:
     strategy:
       matrix:
         python: ["3.6", "3.7", "3.8", "3.9"]
+    env:
+      PYTHON_VERSION: ${{matrix.python}}
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python ${{matrix.python}}
@@ -17,4 +19,11 @@ jobs:
           python -m pip install --upgrade pip
           pip install -e .[testing]
       - name: Run pytest
-        run: pytest --cache-clear
+        run: |
+          pytest --cache-clear --cov=./ --cov-report=xml --cov-report=html
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: ./coverage.xml
+          env_vars: RUNNER_OS,PYTHON_VERSION,CI,GITHUB_SHA,RUNNER_OS,GITHUB_RUN_ID