Using `.pre-commit-config` as a linter and test link check

I guess pre-commit is a good suggestion to let the project clean, and also check the new PRs if they correspond to the linting rules.

For example:

I use https://github.com/pre-commit/pre-commit-hooks for checking:

hooks:
      - id: check-merge-conflict
      - id: check-added-large-files
      - id: check-ast
      - id: check-symlinks
      - id: trailing-whitespace
      - id: check-json
      - id: debug-statements
      - id: pretty-format-json

For sorting imports, I use https://github.com/PyCQA/isort with the black profile.
I use https://gitlab.com/pycqa/flake8 also for applying all style rules.

I will try to describe this issue in a PR.

sqlalchemy / mako

Using `.pre-commit-config` as a linter and test link check #344