Use py3.9 for dev tools.

[adiroiban]

Scope

These are the changes I made on my local branch while working on the TRUSTED CERTIFICATE feature so that I can run more tests locally without having to install 3.7 and 3.8

I have 2.7 and 3.9 installed. It would be nice to not have to install 3.7 just to run the documentation checks for pem :)

Here is the summary on my system for tox

  lint: commands succeeded
  mypy: commands succeeded
  py27-twisted: commands succeeded
  py27: commands succeeded
ERROR:  py35-twisted: InterpreterNotFound: python3.5
ERROR:  py35: InterpreterNotFound: python3.5
ERROR:  py36-twisted: InterpreterNotFound: python3.6
ERROR:  py36: InterpreterNotFound: python3.6
ERROR:  py37-twisted: InterpreterNotFound: python3.7
ERROR:  py37: InterpreterNotFound: python3.7
ERROR:  py38-twisted: InterpreterNotFound: python3.8
ERROR:  py38: InterpreterNotFound: python3.8
  py39-twisted: commands succeeded
  py39: commands succeeded
  manifest: commands succeeded
  docs: commands succeeded
  pypi-description: commands succeeded
  coverage-report: commands succeeded

Feel free to close this as won't fix if you think that 3.7 and 3.8 should be pined.

Pull Request Check List

This is just a friendly reminder about the most common mistakes. Please make sure that you tick all boxes. But please read our contribution guide at least once, it will save you unnecessary review cycles!

If an item doesn't apply to your pull request, check it anyway to make it apparent that there's nothing left to do.

• [NA] Added tests for changed code.
• [NA] Updated documentation for changed code.
  • [NA] New functions/classes have to be added to docs/api.rst by hand.
  • [NA] Changed/added classes/methods/functions have appropriate versionadded, versionchanged, or deprecated directives. Find the appropriate next version in our __init__.py file.
• [NA] Documentation in .rst files is written using semantic newlines.
• [NA] Changes (and possible deprecations) are documented in the changelog.

[hynek]

I used to do but it kept causing problems unfortunately. I'd be rather open to bump them to 3.9.

[adiroiban]

I have updated to explicitly use 3.9 everywhere for dev tools :) Cheers

[hynek]

Hi, sorry I believe I've fixed it in #56 when dropping the junk that annoyed you.