let travis test with python 3.4
we can now use the official django-behave repository.
...but we have to upgrade feedparser for py 3.4
new clean_html method, using BeautifulSoup4.
save bytes to the archive in python 3.4
simplify voting manager defaults.
replace pathod with httpretty

...because I gave up on pathods python3 branch for the moment.
urljoin lives in urllib.parse in python3.4
fix article serializer exceptions.