add flake8 to CI

.flake8

@@ -0,0 +1,3 @@
+[flake8]
+exclude=.git,__pycache__,migrations,management/commands/archive
+max-line-length=120

.github/workflows/ci-flake8.yml

@@ -0,0 +1,25 @@
+name: ci-flake8
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      max-parallel: 4
+      matrix:
+        python-version: ["3.10"]
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install Dependencies
+      run: |
+        pip install flake8
+    - name: Run flake8
+      run: |
+        flake8 -v .