Update CI config

Add .flake8 config file Add black experimental long string processing

.github/workflows/linting.yaml

@@ -19,7 +19,9 @@ jobs:
           architecture: 'x64'
       - name: find trailing whitespace
         uses: harupy/find-trailing-whitespace@master
-      - name: Install dependencies
+      - name: Run black
+        uses: psf/black@stable
+      - name: Install flake8
         run: |
           python -m pip install --upgrade pip
           pip install flake8