Bug 23677: Unit tests

Bug 23677: Unit tests

This patch introduces tests for the GET /biblios/{biblio_id} endpoint.
It tries to cover all the use cases.

To test:
- Apply this patchset
- Run:
  $ kshell
 k$ prove t/db_dependent/api/v1/biblios.t
=> SUCCESS: Tests pass!
- Use Postman (or your favourite tool) to test the API
=> SUCCESS: Works as expected!
- Sign off :-D

Signed-off-by: Arthur Suzuki <arthur.suzuki@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>