Failed example:
    config = activate_modules('party')
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib64/python2.7/doctest.py", line 1315, in __run
        compileflags, 1) in test.globs
      File "<doctest scenario_party_replace.rst[2]>", line 1, in <module>
        config = activate_modules('party')
      File "/home/karla/.virtualenvs/trytond4.2-py2-dev-dow/lib/python2.7/site-packages/trytond/tests/tools.py", line 21, in activate_modules
        Module.click(modules, 'activate')
    TypeError: unbound method click() must be called with ir.module instance as first argument (got list instance instead)