The `type: :feature` is automatically detected by RSpec because these
tests are inside the `spec/features` folder. Using `feature` re-adds a
`type: :feature` to these files, which will result in a conflict when we
upgrade to Rails 5.1's system tests.
Because of this change, we also need to change `background` to `before`
or else these tests will fail.
This spec used to pass, because even though there were no budgets, as
Budget.current returned an array, it gracefully handled situations
without budgets
Now we assume that there can only be a single current budget, and so
calling any method of budget will raise an exception unless there is a
current budget present
Valuators should not access this page when there is no budget present,
however it might be wise to create an issue to cover this case, just in
case
