Travis error on Python2.6

[lurch]

Looking at https://travis-ci.org/giampaolo/pyftpdlib/jobs/166424021 it's failing with AttributeError: 'module' object has no attribute 'OrderedDict' somewhere deep within the flake8 code.

I did a bit of searching and found https://flake8.pycqa.org/en/latest/release-notes/3.0.0.html from which it looks like flake8 2.6.2 was the last version to support Python 2.6, so perhaps your tox.ini needs to be updated as necessary, and then maybe the Travis tests would pass on Python 2.6?

And on a side-note: Why does Travis test Python versions 2.6, 2.7, 3.3, 3.4 and 3.5, but Appveyor only test 2.7, 3.3 and 3.4? (and tox.ini includes py32, which neither of .travis.yml or appveyor.yml do) Found these links, which may be useful: https://docs.travis-ci.com/user/languages/python/ https://www.appveyor.com/docs/installed-software/#python