fixed connection closing issues in fixtures

tests/fixtures/customer_fixtures.py

@@ -18,6 +18,8 @@ def test_customer(db, test_vendor):
     db.add(customer)
     db.commit()
     db.refresh(customer)
+    # Expunge customer from session to prevent ResourceWarning about unclosed connections
+    db.expunge(customer)
     return customer
 
 
@@ -39,4 +41,6 @@ def test_customer_address(db, test_vendor, test_customer):
     db.add(address)
     db.commit()
     db.refresh(address)
+    # Expunge address from session to prevent ResourceWarning about unclosed connections
+    db.expunge(address)
     return address