Install coveralls

Author: fayazkhan

.github/workflows/run-tests.yml

@@ -39,7 +39,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install SQLAlchemy~=${{ matrix.sqlalchemy-version }}
-        pip install -r requirements.txt -r requirements-test.txt
+        pip install -r requirements.txt -r requirements-test.txt coveralls
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names