Bug 17716: Remove itemtype-related t/db_dependent/CourseReserves.t

Bug 17716: Remove itemtype-related t/db_dependent/CourseReserves.t

This patch makes t/db_dependent/CourseReserves.t create
good sample data for its tests. It does so by creating a random
itemtype.

To test:
- Run
  $ prove t/db_dependent/CourseReserves.t
=> FAIL: lots of warnings about "item-level_itypes set but no itemtype
  set for item"
- Apply the patch
- Run:
  $ prove t/db_dependent/CourseReserves.t
=> SUCCESS: Tests are green, and no warnings.
- Sign off :-D

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>