[FIX] pep8 line length to 80

activate pep8 check in travis, and add no qa on scenario while waiting improvement of quality-tools.
This is a PEP8 commit only, underling code quality will not be improved in this PR
Do you think `'N/A'` should be translated? For example, some localizations only have it in minuscule `n/a` and some only in caps.