Deprecate Travis and use Github Actions

[scottwernervt]

• Move and delete tox.ini into pyproject.toml
• Update pre-commit package dependencies
• New pre-commit hooks
  • check-ast
  • check-toml
  • end-of-file-fixer
  • trailing-whitespace
• This command has been deprecated. Use twine check instead: https://packaging.python.org/guides/making-a-pypi-friendly-readme#validating-restructuredtext-markup
• Move pytest config to pyproject.toml
• Setup tox-gh-actions
• Remove .travis.yml and Travis CI auth or tokens