Remove nth occurrence of an object from a collection/object.

[elrayle]

Objects can repeat in a collection and in an object. The RemoveObjectFromCollection and RemoveObjectFromObject services need to support specifying which occurrence to remove. See notes in those services and see the following tests in remove_object_from_collection_spec and remove_object_from_object_spec.

xit 'should remove first occurrence'
xit 'should remove last occurrence'
xit 'should remove nth occurrence'

[elrayle]

DEPENDENCY: samvera-deprecated/activefedora-aggregation#46 for more information.

Proposed syntax:

# delete 2nd occurrence of do_child1
do_parent.members.delete( do_child1, 2 )   # => do_child1

[jrgriffiniii]

Closing this due to the age of the issue (I am sorry, please let me know should this be reopened).