ci: check style with black

.github/workflows/pythonapp.yml

@@ -15,25 +15,23 @@ on:
 
 jobs:
   quality:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
-    - name: Set up Python 3.8
+    - uses: actions/checkout@v2
+    - name: Set up Python 3.x
       uses: actions/setup-python@v1
       with:
-        python-version: 3.8
+        python-version: 3.x
     - name: Install dependencies
       run: |
-        python -m pip install --upgrade pip
+        python -m pip install --upgrade pip wheel
         pip install -r requirements.txt
+        pip3 install black
 
     - name: Lint with flake8
       run: |
+        black --check guiscrcpy --exclude guiscrcpy/ui
         pip install flake8
-        # stop the build if there are Python syntax errors or undefined names
-        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
-        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-        flake8 --per-file-ignores='setup.py:E501' 
         
     - name: Test setup.py
       run: |