Add upper limit to pyflake's version <3.0 to support handling of python 2.x # type: comments

[psasselum]

The latest pyflake version removed handling of python 2.x # type: comments. As the dependency was not upper limited in release of autoflake, none of the available release of autoflake handle's 2.X style typing. It would be very convenient to have a last release that support it in autoflake before allowing pyflake > 3.0 again.

[Pierre-Sassoulas]

It seem that the supported version is 3.7 so something like this, which would have worked without a major release if python 3.5 was still supported would not make a lot of sense:

    "pyflakes>=1.1.0,<3;python_version<'3.6'",
    "pyflakes>=1.1.0,<4;python_version>='3.6'",

Beside 2.x style typing can still be used in python version > 3.5. I think releasing a major with pyflakes>=1.1.0,<4 immediately after the next release make sense. That way there's a last release for 2.x typing and the major can announce the breaking change.

[bityob]

For those who use pre-commit with autoflake,
you can pin the pyflakes dependency like this:

  - repo: https://github.com/PyCQA/autoflake.git
    rev: v1.4
    hooks:
      - id: autoflake
        args:
          - --in-place
          - --remove-unused-variables
          - --remove-all-unused-imports
          - --ignore-init-module-imports
          - --remove-duplicate-keys
        language_version: python3
        additional_dependencies:
          - pyflakes>=1.1.0,<3

[psasselum]

Thank you for the quick release 👌