Boost `ltitop` quality

[hidmic]

Rationale

As of today, ltitop is still pretty much a proof-of-concept. Thus, its code needs polishing, test coverage must be increased, and a continuous integration process be put in place to ensure it stays healthy over time.

Definition of Done

• Add pre-commit hooks
  • Reformat sources using black and blacken-docs
  • Reformat sources susing isort.
  • Lint sources using flake8.
  • Statically check sources using mypy.
  • Lint tox.ini using tox-ini-fmt
• Test for Python 3.5+ using tox
• Measure coverage using pytest-cov
• Configure Github Actions CI
  • Test job to ensure all unit tests pass
  • Lint job to ensure all linters pass
• Test all public APIs (~80% coverage)
• Type annotate all public APIs.

Additional considerations

Consider Codecov or Coveralls for coverage tracking.