Update tox to 2.4.0

[pyup-bot]

There's a new version of tox available.
You are currently using 2.3.1. I have updated it to 2.4.0

These links might come in handy: PyPi | Changelog | Docs

Changelog

2.4.0

---

• remove PYTHONPATH from environment during the install phase because a
  tox-run should not have hidden dependencies and the test commands will also
  not see a PYTHONPATH. If this causes unforeseen problems it may be
  reverted in a bugfix release. Thanks Jason R. Coombs.
• fix issue352: prevent a configuration where envdir==toxinidir and
  refine docs to warn people about changing "envdir". Thanks Oliver Bestwalter and holger krekel.
• fix issue375, fix issue330: warn against tox-setup.py integration as
  "setup.py test" should really just test with the current interpreter. Thanks Ronny Pfannschmidt.
• fix issue302: allow cross-testenv substitution where we substitute
  with {x,y} generative syntax. Thanks Andrew Pashkin.
• fix issue212: allow escaping curly brace chars "{" and "}" if you need the
  chars "{" and "}" to appear in your commands or other ini values.
  Thanks John Vandenberg.
• addresses issue66: add --workdir option to override where tox stores its ".tox" directory
  and all of the virtualenv environment. Thanks Danring.
• introduce per-venv list_dependencies_command which defaults
  to "pip freeze" to obtain the list of installed packages.
  Thanks Ted Shaw, Holger Krekel.
• close issue66: add documentation to jenkins page on how to avoid
  "too long shebang" lines when calling pip from tox. Note that we
  can not use "python -m pip install X" by default because the latter
  adds the CWD and pip will think X is installed if it is there.
  "pip install X" does not do that.
• new list_dependencies_command to influence how tox determines
  which dependencies are installed in a testenv.
• (experimental) New feature: When a search for a config file fails, tox tries loading
  setup.cfg with a section prefix of "tox".
• fix issue275: Introduce hooks `tox_runtest_preand tox_runtest_post`` which run before and after the tests of a venv,
  respectively. Thanks to Matthew Schinckel and itxaka serrano.
• fix issue317: evaluate minversion before tox config is parsed completely.
  Thanks Sachi King for the PR.
• added the "extras" environment option to specify the extras to use when doing the
  sdist or develop install. Contributed by Alex Grönholm.
• use pytest-catchlog instead of pytest-capturelog (latter is not
  maintained, uses deprecated pytest API)

2.3.2

---

• fix issue314: fix command invocation with .py scripts on windows.
• fix issue279: allow cross-section substitution when the value contains
  posargs. Thanks Sachi King for the PR.

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[codecov-io]

Current coverage is 100% (diff: 100%)

Merging #18 into master will not change coverage

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