Add rec_names to avoid key error

Sometimes Odoo will try to find the name of an object
if the name column doesn't exist and there is no _rec_name it will result in: KeyError: "Field 'name' does not exist in object 'browse_record(travel.rental.service, 1)'"
Merge pull request #8 from savoirfairelinux/rec_name

Add rec_names to avoid key error