Use dev for optional development dependencies

.github/workflows/testing.yml

@@ -30,7 +30,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install .[development]
+        python -m pip install .[dev]
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names