Moves simplecov to rails_helper, ignores .bundle
Moves simplecov to rails_helper, ignores .bundle

As per rspec best practice, I'm moving customisations to rails_helper. I
tend to install gems in `.bundle`, so I'm adding that to the simplecov
ignore list as well.

ministryofjustice/peoplefinder,ministryofjustice/peoplefinder,ministryofjustice/peoplefinder,ministryofjustice/peoplefinder,ministryofjustice/peoplefinder