Refactor tariff instanciation
Tariff "service" instantiation defines the set of attributes (product_id, additional_bonds, promotions) that the MM API requires.
- Tariff.get_MM_tariff_code is removed
- AdditionalBond2 from Tariffs model is not used anymore
RelTariffs3P is model that relates two Tariffs instances by stating their correspondence (data and minutes) and which of them is the 3P version (cheaper, associated with fiber)
Edited by Gerard Funosas