Add tests for known previous issue.
Add tests for known previous issue.

fivetanley/ember-inflector,stefanpenner/ember-inflector,jerel/ember-inflector,grapho/ember-inflector,Eric-Guo/ember-inflector,greyhwndz/ember-inflector,fivetanley/ember-inflector,greyhwndz/ember-inflector,stefanpenner/ember-inflector,Eric-Guo/ember-inflector,grapho/ember-inflector,jerel/ember-inflector