🎨 Bring Python code into compliance with Black and Flake8 (#121)

* Ignore Flake8 unused import error F401

https://flake8.readthedocs.io/en/latest/user/error-codes.html

The apparently unused imports may be needed for SQLAlchemy.

As the code comment says:

make sure all SQL Alchemy models are imported before initializing DB
otherwise, SQL Alchemy might fail to initialize properly relationships

See GitHub 28 and 29

* Ignore Flake8 unused variable error F841

https://flake8.readthedocs.io/en/latest/user/error-codes.html

The apparently unused variables may be needed for tests.

* Bring line length into compliance with Black

Should be 88 characters.

* Format alembic code with Black

{{cookiecutter.project_slug}}/backend/app/app/core/config.py

@@ -1,4 +1,3 @@
-import os
 import secrets
 from typing import List
 
@@ -89,4 +88,5 @@ class Settings(BaseSettings):
     class Config:
         case_sensitive = True
 
+
 settings = Settings()