These variables can be considered a block, and so removing them doesn't
make the test much harder to undestand.
Sometimes these variables formed the setup, sometimes they formed an
isolated part of the setup, and sometimes they were the part of the test
that made the test different from other tests.
In the scenario where we want to test scopes and use `match_array`, we
usually declare variables we never use, which raises a warning in the
Ruby interpreter (since the main cause for an unused variable is a
typo).
So I've decided to just split the tests into cases where every record is
returned and cases were no records are returned, just like we do in
other places.
There are several other options we've considered:
1. Don't declare unused variables, but declare the ones we use
2. Prefix unused variables with un underscore
3. Declare just one variable being an array containing all elements, and
access the elements using Array#[]
4. Don't declare any variables, and compare results against attributes
such as titles
None of these options was met with enthusiasm.
Unless we're using the booth assignment for something else in the test,
when creating a voter from booth, specifying the poll and the booth is
enough to create a booth assignment.
