Fix flake8.

pos_barcode_tare/models/barcode_rule.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-from openerp import _, models, fields, api
+from openerp import _, models, api
 
 
 class BarcodeRule(models.Model):
@@ -11,4 +11,4 @@ class BarcodeRule(models.Model):
         res = super(BarcodeRule, self)._get_type_selection()
         res.append(
             ('tare', _('Tare')))
-        return res
+        return res