Impacted versions:10

Steps to reproduce:
Following the code in https://www.odoo.com/documentation/10.0/api_integration.html both in a fresh install and against 'https://demo.odoo.com/start' trows a type error

Current behavior:
Now I get an error when executing:

```
ids = models.execute_kw(db, uid, password,  'res.partner', 'search',
    [[['is_company', '=', True], ['customer', '=', True]]],
    {'limit': 1})
[record] = models.execute_kw(db, uid, password,
    'res.partner', 'read', [ids])
# count the number of fields fetched by default
len(record)
```

In particular it seems to be a type error (cannot marshal class odoo.tools.float_utils.float_precision)

Expected behavior:
I would expect it to behave as in the documentation

""" Convert the old-API default ``value`` to the old API. """
    return value
class MetaField(type):
    """ Metaclass for field classes. """
    by_type = {}
    def __new__(meta, name, bases, attrs):
        """ Combine the ``_slots`` dict from parent classes, and determine
        ``__slots__`` for them on the new class.
        """
        base_slots = {}
        for base in reversed(bases):
            base_slots.update(getattr(base, '_slots', ()))
        slots = dict(base_slots)
        slots.update(attrs.get('_slots', ()))
        attrs['__slots__'] = set(slots) - set(base_slots)
        attrs['_slots'] = slots
        return type.__new__(meta, name, bases, attrs)
    def __init__(cls, name, bases, attrs):