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

type = 'boolean'
    def convert_to_cache(self, value, record, validate=True):
        return bool(value)
    def convert_to_export(self, value, record):
        if record._context.get('export_raw_data'):
            return value
        return ustr(value)
class Integer(Field):
    type = 'integer'
    _slots = {
        'group_operator': 'sum',
    }
    _description_group_operator = property(attrgetter('group_operator'))
    def convert_to_cache(self, value, record, validate=True):