Cast the voluntary_contribution to int

See merge request coopdevs/odoo-somconnexio-python-client!2

Create version 0.1.0

See merge request coopdevs/odoo-somconnexio-python-client!1

We need a endpoint to validate that a VAT number exists in our system.
With this resource we can cover this requirement.

Usage:

partner = Partner.search_by_vat(vat="XXX")

We don't need to send this information because we only use one share
product and always 1 order part if the type is `new`. We can manage this
cases in Odoo instead of in the external service.

This resource provide two methods: `mobile_list` and `broadband_list` to
list the providers (id and name). Return a list of Provider objects.

* Fix the url_paths
* Fix to client get to use the query parameters
* Add BadRequestError and ResourceNotFound exceptions

 exception and refactor the client exceptions

Temporal fix to continue with the Tryton integration. In the future we
can remove this defaults if they are not needed.

When we want to calll to Odoo we don't have any model created, only the
request data in JSON.

We add the mappers to this repository because we can fake the
PartnerForm and the contract forms testing the models and develop more
faster ans secure.

This two new classes and the testing tools addes can be removed when we
close the Tryton webforms.

The zen of Python
https://www.python.org/dev/peps/pep-0020/#id2