fix tests always "succeed"
fix tests always "succeed"

The problem is that runtests.py used in tox always returns with exitcode 0 whatever happens. Tox (and in extension Travis) needs an exitcode != 0 to be able to know that something went wrong.
ababic/wagtailmenus,ababic/wagtailmenus,rkhleics/wagtailmenus,ababic/wagtailmenus,rkhleics/wagtailmenus,rkhleics/wagtailmenus