typos on wiki 5.0/step10

[pierre-malis-coopengo]

There is quite a few typos on page 10,
especially regarding the classes definitions:

library.user:

checkouts = fields.One2Many('library.user.checkout', 'user', 'Checkouts')

library.user.checkout:

user = fields.Many2One('library.user', 'User', required=True,
    ondelete='CASCADE', select=True)
exemplary = fields.Many2One('library.book.exemplary', 'Exemplary',
    required=True, ondelete='CASCADE', select=True)

should be remplaced by this:

class User(ModelSQL, ModelView):
    'Library User'
    __name__ = 'library.user'

    checkouts = fields.One2Many('library.user.checkout', 'user', 'Checkouts')


class Checkout(ModelSQL, ModelView):
    'Checkout'
    __name__ = 'library.user.checkout'

    user = fields.Many2One('library.user', 'User', required=True,
        ondelete='CASCADE', select=True)
    exemplary = fields.Many2One('library.book.exemplary', 'Exemplary',
        required=True, ondelete='CASCADE', select=True)