This patch adds tests for the new method to be introduced. It also moves
the tests for Koha::Biblio->subscriptions to the Biblio.t where it
really belongs.
To test, run this tests along with the patch implementing the new
method.
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io> Signed-off-by: Nick Clemens <nick@bywatersolutions.com> Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org> Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>