Fix MOAR specs related to package api changes

Had to modify the order factory which caused a bunch of other specs to
fail. Hopefully now it has a more reasonable approach which is first
create line items list then shipments and then update! itself.
Remove Stock::RemainingPacker (not referenced anywhere)

Had some broken specs there and decided to remove it rather then fix the
specs. It's not used anywhere and it's not clear why it exists so we
might be better off without it