Updates for purchase order line items

- Display list of line items
- Add a form to create a new line item

InvenTree/order/forms.py

@@ -0,0 +1,23 @@
+"""
+Django Forms for interacting with Order objects
+"""
+
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from InvenTree.forms import HelperForm
+
+from .models import PurchaseOrder, PurchaseOrderLineItem
+
+
+class EditPurchaseOrderLineItemForm(HelperForm):
+
+    class Meta:
+        model = PurchaseOrderLineItem
+        fields = [
+            'order',
+            'part',
+            'quantity',
+            'reference',
+            'received'
+        ]