Add default billing entity from origin

ref #198

src/tests/conftest.py

@@ -3,6 +3,7 @@ import base64
 import pytest
 
 from servala.core.models import (
+    BillingEntity,
     Organization,
     OrganizationMembership,
     OrganizationOrigin,
@@ -21,6 +22,11 @@ def origin():
     return OrganizationOrigin.objects.create(name="TESTORIGIN")
 
 
+@pytest.fixture
+def billing_entity():
+    return BillingEntity.objects.create(name="Test Entity")
+
+
 @pytest.fixture
 def organization(origin):
     return Organization.objects.create(name="Test Org", origin=origin)