Add MIN_API_VERSION to SalesOrderAllocation model. Workaround for old versions of server

Author: miggland

inventree/sales_order.py

@@ -196,6 +196,7 @@ class SalesOrderAllocation(
 ):
     """Class representing the SalesOrderAllocation database model."""
 
+    MIN_API_VERSION = 267
     URL = 'order/so-allocation'
 
     def getOrder(self):
@@ -204,7 +205,7 @@ def getOrder(self):
 
     def getShipment(self):
         """Return the SalesOrderShipment to which this SalesOrderAllocation belongs."""
-        from sales_order import SalesOrderShipment
+        # from sales_order import SalesOrderShipment
         return SalesOrderShipment(self._api, self.shipment)
 
     def getLineItem(self):
@@ -275,7 +276,10 @@ def allocations(self):
 
         Note: This is an overload of getAllocations() method, for legacy compatibility.
         """
-        return self.getAllocations()
+        try:
+            return self.getAllocations()
+        except NotImplementedError:
+            return self._data['allocations']
 
     def complete(
         self,