Install dev dependencies in the pipeline

Author: php1ic

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -e .
+        pip install -e '.[dev]'
     - name: Test with pytest
       run: |
         coverage run -m pytest -v && coverage xml