refactor tests
change date format of archive view
add language related tests
new TranslationMixin for views
added no timezone tests
add comment on how to run the tests
refactor tests
add language related tests
limit authors to staff members
update tests so site is not required
add same category template tag
same categories function does not belong in the model.
fix factories
test suite passes again
test four letter language codes
add test for all languages override
remove unused import