Fix flake8 issues since release 3.6.0
Flake8 had a new release which raise new issues, namely:
W504: line break after binary operator
F841: local variable 'ex' is assigned to but never used
W605: invalid escape sequence
F821: undefined name 'buffer' (noqa seems the only way to avoid this false positive)
Also pin flake8>=3.6 in our tests and make explicit that we use python3 to run
flake8 tests.
.. -*- coding: utf-8 -*-
A little history...
===================
*CubicWeb* is a semantic web application framework that Logilab_ started
developing in 2001 as an offspring of its Narval_ research project. *CubicWeb*
is written in Python and includes a data server and a web engine.
Its data server publishes data federated from different sources like
SQL databases, LDAP directories, `VCS`_ repositories or even from other
CubicWeb data servers.
.. _`VCS`: http://en.wikipedia.org/wiki/Revision_control
Its web engine was designed to let the final user control what content to select
and how to display it. It allows one to browse the federated data sources and
display the results with the rendering that best fits the context. This
flexibility of the user interface gives back to the user some capabilities
usually only accessible to application developers.
*CubicWeb* has been developed by Logilab_ and used in-house for many years
before it was first installed for its clients in 2006 as version 2.
In 2008, *CubicWeb* version 3 became downloadable for free under the
terms of the LGPL license. Its community is now steadily growing
without hampering the fast-paced stream of changes thanks to the time
and energy originally put in the design of the framework.
.. _Narval: http://www.logilab.org/project/narval-moved
.. _Logilab: http://www.logilab.fr/