Invoice and shipment pluging doesn't work

[gonzaloebiz]

Issue Description

Both plugins for afterSave function is never executed

Preconditions

1. Any version of magento with the last version of mc-magento2 (at the moment 1.x.50)
2. Create an order with at least 2 products

Steps to reproduce

1. Enter the first invoice (or shipment)
2. Wait until the orders is synched
3. When the order is synched, enter a second invoice (or shipment)

Actual and Expected result

Expected result:
When adding the second invoice or shipment the order must be marked for resync

Actual result:
The order is not marked