Log Message:
devel/ruby-diva: added ruby-diva-0.3.0.

This gem is required by forthcoming mikutter-3.6.0.

This library is an implementation of expression for handling things.
It replaces Retriever module of mikutter.

Diva::Model is a common interface of all resources handled by mikutter.
By handling data as a subclass of Diva::Model as necessary, you can
obtain a common interface and it is useful for cooperation among
mikutter plugins.