We were only using it in a few places.
I've left the current `final: true` statement in a few places where
using a trait would break vertical alignment, just in case.
Note we usually cannot make it simple because officer assignments are
usually assigned to both a poll and a booth, and on a certain date.
However, in the few cases where the booth nor the date don't matter, we
can make the code a bit easier to read.
We're using `eq` and `match_array` in most places, but there were a few
places where we were still checking each element is included in the
array. This is a bit dangerous, because the array could have duplicate
elements, and we wouldn't detect them with `include`.
While it could be argued we're hiding the real way we've defined
associations in our models, the tests are so much easier to read when we
don't have so many lines just creating data.
Furthermore, developers who care about vertically aligning the code will
be glad to see some variables disrupting this alignment are now gone.
Avoid to raise an exception `Module::DelegationError' when trying to
show the name and/or email of a poll officer whose user account has
been deleted.
We'll show a message "User deleted" and "Email deleted" instead.
This way we can easily add a test which will fail if by accident we
change the method to use `Date.today`. Until now using `Date.today`
would only fail if we ran specs in a time zone with a different date.
