Log Message:
py-codestyle: updated to 2.6.0

2.6.0:

Changes:
* E306: fix detection inside ``async def``.
* E301: fix regression disallowing decorated one-liners.
* E714: fix false positive with chained ``is not``.

2.6.0a1:

New checks:
* E225: require whitespace around ``and`` ``in`` ``is`` and ``or``.

Changes:
* E117: fix indentation using tabs by treating as 8-space indents.
* E721: fix false positive with names containg ``istype``.
* E741: allow ``l`` as a named argument in a function call.
* E302: fix false-negative with decorated functions.
* W504: ellipsis (``...``) is no longer treated as a binary operator.
* E402: allow ``with``, ``if``, ``elif``, ``else`` to guard imports.
* Add support for assignment expressions ``:=`` (PEP 572).
* Add support for positional-only arguments ``/`` (PEP 570).
* Add support for python 3.8.
* Add support for matrix multiplication operator ``@`` (PEP 465).
* Support visual indent for continuation lines for ``with`` / ``assert`` /
  ``raise``.
* E302: allow two blank lines after a block of one-liners.
* E302: allow two-and-fewer newlines at the top of the file.