Proposed fix for an issue where CanCanCan breaks when the model is named "Action"

Newbie Ruby dev here! *waves*

I -think- this fixes issue #125, at least partially.

The problem occurs in resource_params_by_namespaced_name. There is a bug due to the key in the hash being the same as the model name, returning a value when it's not supposed to.

Would appreciate any review (relatively new to Ruby, as mentioned). Thanks.