Version 0.2.0

This adds the namespace decorator, intended for use on class_only classes that just define constant attributes.

For example, given the following class:

from class_only_design import namespace

@namespace
class ColourConstants:
    RED = 'FF0000'
    GREEN = '00FF00'
    BLUE = '0000FF'

The namespace decorator provides the mutability and instanciation protections of class_only, but also:

• makes the class iterable, e.g.:

  list(ColourConstants) # returns ['FF0000', '00FF00', '0000FF']

• adds a special attribute, nameof which returns the name of the class attribute:

  ColourConstants.nameof.RED # returns 'RED'

It also improves the underlying implementation of the class decorators. They no longer modify the class hierarchy.