Proposed modification to the attribute? method of the attributes module to use the unobservable_read_attribute when available

attributes.rb

    def attribute?(key)
      # this method is used only for conditional type access.  
      # When included on an object with read observations, don't count this as an observable read
      if respond_to? :unobservable_read_attribute
        value = unobservable_read_attribute key
      else
        value = read_attribute key
      end

      return false if value.nil?
      return false if value.respond_to?(:empty?) && value.empty?

      value.to_s !~ /^(false|no|never)$/i
    end