Clean-up CI setup

.github/workflows/pythonapp.yml

@@ -23,10 +23,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install .
-    - name: Install extras
-      run: |
-        pip install -r requirements.txt
+        pip install .[all]
     - name: Lint with flake8
       run: |
         pip install flake8