[web/test] use unicode object as user login
(py.warnings) WARNING: /home/jcr/src/cw/cubicweb/devtools/testlib.py:206: DeprecationWarning: Sanitizing an input dictionary with str values, please check your data (key = 'login')
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html