[FIX] sale_stock: fix msg argument in assertion

third positional argument is places not msg (which expects a number not a str)
https://docs.python.org/2/library/unittest.html#unittest.TestCase.assertAlmostEqual

fixes errors like these:
 if round(abs(second-first), places) == 0:
 TypeError: 'str' object cannot be interpreted as an integer

and gives the intended message when assertion is errornous

addons/sale_stock/tests/test_sale_stock.py

@@ -176,14 +176,14 @@ class TestSaleStock(TestSale):
 
         # Check invoice
         self.assertEqual(self.so.invoice_status, 'to invoice', 'Sale Stock: so invoice_status should be "to invoice" instead of "%s" after picking return' % self.so.invoice_status)
-        self.assertAlmostEqual(self.so.order_line[0].qty_delivered, 3.0, 'Sale Stock: delivered quantity should be 3.0 instead of "%s" after picking return' % self.so.order_line[0].qty_delivered)
+        self.assertAlmostEqual(self.so.order_line[0].qty_delivered, 3.0, msg='Sale Stock: delivered quantity should be 3.0 instead of "%s" after picking return' % self.so.order_line[0].qty_delivered)
         # let's do an invoice with refunds
         adv_wiz = self.env['sale.advance.payment.inv'].with_context(active_ids=[self.so.id]).create({
             'advance_payment_method': 'all',
         })
         adv_wiz.with_context(open_invoices=True).create_invoices()
         self.inv_2 = self.so.invoice_ids.filtered(lambda r: r.state == 'draft')
-        self.assertAlmostEqual(self.inv_2.invoice_line_ids[0].quantity, 2.0, 'Sale Stock: refund quantity on the invoice should be 2.0 instead of "%s".' % self.inv_2.invoice_line_ids[0].quantity)
+        self.assertAlmostEqual(self.inv_2.invoice_line_ids[0].quantity, 2.0, msg='Sale Stock: refund quantity on the invoice should be 2.0 instead of "%s".' % self.inv_2.invoice_line_ids[0].quantity)
         self.assertEqual(self.so.invoice_status, 'no', 'Sale Stock: so invoice_status should be "no" instead of "%s" after invoicing the return' % self.so.invoice_status)
 
     def test_03_sale_stock_delivery_partial(self):