Flake8 not pass if 3.7 python version

[VladislavPatrushev]

Describe the bug When i run github action with python version 3.7. Flake8 raise SyntaxError on 179 line. https://github.com/eora-ai/torchok/blob/dev/torchok/models/backbones/beit.py

To Reproduce Replace .github/workflows/flake8_checks.yaml below code snippet.

on:
  push:
    branches: [dev]
  pull_request: 
    branches: [dev]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Install python
        uses: actions/setup-python@v2
        with:
          python-version: 3.7
      - name: Install deps
        run: |
          python -m pip install --upgrade pip
          pip install flake8
      - name: Run flake8
        run: flake8 .```

[VladislavPatrushev]

https://docs.python.org/3.8/whatsnew/3.8.html In python 3.8 add feature for unpack in return without enclosing parentheses