Add coverage to the github action.

.github/workflows/test_ci.yml

@@ -28,6 +28,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
+	  pip install coverage
       - name: Test & publish code coverage
         uses: paambaati/codeclimate-action@v2.6.0
         env: