CI: Collect coverage from GHA Pytest run

.github/workflows/test.yml

@@ -34,7 +34,7 b' jobs:'
         python -m pip install --upgrade pip setuptools wheel
         python -m pip install --upgrade -e file://$PWD#egg=ipython[test]
         python -m pip install --upgrade --upgrade-strategy eager trio curio 
-        python -m pip install --upgrade pytest pytest-trio 'matplotlib!=3.2.0'
+        python -m pip install --upgrade pytest pytest-cov pytest-trio 'matplotlib!=3.2.0'
         python -m pip install --upgrade check-manifest pytest-cov anyio
     - name: Check manifest
       run: check-manifest
@@ -45,6 +45,6 b' jobs:'
         cp /tmp/.coverage ./
     - name: pytest
       run: |
-        pytest -v
+        pytest -v --cov --cov-report=xml
     - name: Upload coverage to Codecov
       uses: codecov/codecov-action@v2