Use a linter tool to adjust code style based on PEP8

[fernandojunior]

Suggested libs:

• flake8 (find lint warnings)
• pylint (find lint warnings)
• black (automatic formater)
• flake8-black (automatic formater based on flake8 warnings)

Configure Github CI/CD to automatically use these libs to find and fix lint warnnigs/erros.

Refs:

• https://github.com/fernandojunior/financial-fraud-detection/blob/master/.github/workflows/pythonpackage.yml