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.
CSS Coding Standards
--------------------
(Draft, to be continued)
:Naming: camelCase
Indentation rules
~~~~~~~~~~~~~~~~~
- 2 espaces avant les propriétés
- pas d'espace avant les ":", un espace après
- 1 seul espace entre les différentes valeurs pour une même propriété
Documentation
~~~~~~~~~~~~~
Please keep rules semantically linked grouped together, with a comment about
what they are for.
Recommendation
~~~~~~~~~~~~~~
- Try to use existing classes rather than introduce new ones
- Keep things as simple as possible while in the framework
- Think about later customization by application
- Avoid introducing a new CSS file for a few lines of CSS, at least while the
framework doesn't include packing functionalities