Some pycodestyle (PEP8) fixes

See merge request !746

pep8 package was renamed to pycodestyle

I have tried to use pytest-codestyle but It seems it not possible
to exclude paths yet: https://github.com/henry0312/pytest-codestyle/issues/32

This is the current occurence:
40      W605 invalid escape sequence '\s'
75      W504 line break after binary operator