Update flake8 to 3.5.0

[pyup-bot]

This PR updates flake8 from 3.4.1 to 3.5.0.

Changelog

3.5.0

-------------------

You can view the `3.5.0 milestone`_ on GitLab for more details.

New Dependency Information
~~~~~~~~~~~~~~~~~~~~~~~~~~

- Allow for PyFlakes 1.6.0 (See also `GitLab359`_)

- Start using new PyCodestyle checks for bare excepts and ambiguous identifier
(See also `GitLab361`_)

Features
~~~~~~~~

- Print out information about configuring VCS hooks (See also `GitLab335`_)

- Allow users to develop plugins "local" to a repository without using
setuptools. See our documentation on local plugins for more information.
(See also `GitLab357`_)

Bugs Fixed
~~~~~~~~~~

- Catch and helpfully report ``UnicodeDecodeError``\ s when parsing
configuration files. (See also `GitLab358`_)


.. all links
.. _3.5.0 milestone:
 https://gitlab.com/pycqa/flake8/milestones/20

.. issue links
.. _GitLab335:
 https://gitlab.com/pycqa/flake8/issues/335
.. _GitLab357:
 https://gitlab.com/pycqa/flake8/issues/357
.. _GitLab358:
 https://gitlab.com/pycqa/flake8/issues/358
.. _GitLab359:
 https://gitlab.com/pycqa/flake8/issues/359
.. _GitLab361:
 https://gitlab.com/pycqa/flake8/issues/361

.. merge request links

Links

• PyPI: https://pypi.org/project/flake8
• Changelog: https://pyup.io/changelogs/flake8/
• Repo: https://gitlab.com/pycqa/flake8