[FIX] partner_firstname: Change _id by id in the method copy_data to avoid problem with the new API

[FIX] partner_firstname : Remove the value checks in tests. With Odoo v8, the value checks in tests raise a Warning "2015-02-05 08:59:44,867 4590 WARNING 00846-develop-v8-9743ea-all openerp.modules.module: Found deprecated fast_suite or checks attribute in test module openerp.addons.partner_firstname.tests. These have no effect in or after version 8.0."
With Runbot, we cannot have any Warning.

partner_firstname/partner.py

@@ -91,7 +91,7 @@ class ResPartner(orm.Model):
 
         return self.write(cursor, uid, partner_id, vals, context=context)
 
-    def copy_data(self, cr, uid, _id, default=None, context=None):
+    def copy_data(self, cr, uid, id, default=None, context=None):
         """
         Avoid to replicate the firstname into the name when duplicating a
         partner
@@ -101,13 +101,13 @@ class ResPartner(orm.Model):
             default = default.copy()
             default['lastname'] = (
                 _('%s (copy)') % self.read(
-                    cr, uid, [_id], ['lastname'], context=context
+                    cr, uid, [id], ['lastname'], context=context
                     )[0]['lastname']
             )
             if default.get('name'):
                 del(default['name'])
         return super(ResPartner, self).copy_data(
-            cr, uid, _id, default, context=context)
+            cr, uid, id, default, context=context)
 
     def create(self, cursor, uid, vals, context=None):
         """

partner_firstname/tests/__init__.py

@@ -29,7 +29,3 @@
 ##############################################################################
 
 from . import test_partner_firstname
-
-checks = [
-    test_partner_firstname
-]