Bug 29670: Unit tests

Bug 29670: Unit tests

This patch adds unit tests for Koha::Edifact::Order->order_line. We now
check that the message segments are created as expected for both the
'ordering' and not 'ordering' case for acquisitions item creation time.

Signed-off-by: Jonathan Field <jonathan.field@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
JD amended patch: spelling segement ==> segment

(cherry picked from commit 67bb6f7b95e848075534127116ead9e8820ac90f)

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>