We weren't showing the details of answers without a description, even if
they had images, videos or documents. Some users found that behavior
unexpected since the description isn't a mandatory field and so they
left it blank, but they added images to that answer and they didn't
appear on the poll page.
Note we had a condition not to show the title of an answer when it had
no description. I think that condition was redundant because answers
without a description weren't loaded in the first place. Anyway, that
condition doesn't make sense anymore because we're displaying answers
with images but no description.
So now we test in depth at the model level, and can be a bit more
relaxed about integration tests for translations.
Note we're defining some extra factories to make sure all translatable
attributes with presence validation rules are mandatory. This way we can
simplify the way we obtain required fields, using `required_attribute?`.
Otherwise, fields having an `unless` condition in their presence
validation rules would count as mandatory even when they're not.
