py-codestyle: updated to 2.5.0

2.5.0:

New checks:
* E117: Over-indented code blocks
* W505: Maximum doc-string length only when configured with --max-doc-length

Changes:
* Remove support for EOL Python 2.6 and 3.3.
* Add E117 error for over-indented code blocks.
* Allow W605 to be silenced by # noqa and fix the position reported by W605
* Allow users to omit blank lines around one-liner definitions of classes and
  functions
* Include the function return annotation (->) as requiring surrounding
  whitespace only on Python 3
* Verify that only names can follow await. Previously we allowed numbers
  and strings.
* Add support for Python 3.7
* Fix detection of annotated argument defaults for E252
* Cprrect the position reported by W504

(adam)