In Rails 4 pre-release, Class.model_name now responds with an instance of ActiveModel::Name

Turns out there was a change in Rails 4 and Class.model_name now responds with an instance of ActiveModel::Name as opposed to a string (as it did in Rails 3)

See more details here: https://gist.github.com/4544950
Here's the rails commit that did it: https://github.com/rails/rails/commit/72cbccb5f77ebbd56b3b82a3eda99b6d640d8084

Resolves: https://github.com/karmi/tire/issues/585