nattrs 0.2.0

• Adds nested_delattr() for deleting attributes / dict members in nested data structures.
• Adds nested_updattr() for updating dicts and class.dict of nested attributes with a dict.
• Adds regex argument to nested_*attr() functions for using regular expression to index attribute names / dict keys.
• Adds getter_default argument to nested_mutattr() to allow better handling of missing attributes.
• Adds Ignore() class to use as default value in nested_getattr() and getter_default in nested_mutattr().
• Removes mutability requirements from type hints when they are unnecessary (only the sub object/Mapping needs to by mutable).
• Adds hexagon bagde.