Check with flake8 after push

.github/workflows/flake.yml

@@ -0,0 +1,24 @@
+name: flake
+
+on: [push, pull_request]
+
+jobs:
+  flake:
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+        python-version: ["3.12"]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Test
+      run: |
+        pip install flake8
+        flake8 .