A "find_by_attribute" finder

Hello guys,

We are using this gem in our app and every time we add `translates :name` to one of our objects, ActiveRecord associated finder `find_by_name` stops working :/
We have devised a simple workaround that might interest some of you but still needs to be added manually everytime:

    def self.find_by_name(name)
      where("name_translations @> hstore('#{I18n.locale}', '#{name}')").first
    end

Here is a pull request adding this feature to your gem :)

Note : has been tested in our app as well and all seems to be working well

Thanks for your feedbacks