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.
.. _Part2:
----------------------
Repository development
----------------------
This part is about developing applications with the *CubicWeb*
framework. It is not concerned with the web system, which is a
separate layer and has its own whole chapter.
.. toctree::
:maxdepth: 2
:numbered:
cubes/index
vreg.rst
datamodel/index
entityclasses/index
devcore/index
repo/index
testing.rst
migration.rst
profiling.rst
fti.rst
dataimport