Fix deprecated ActiveModel::Errors#add options

lib/couchrest/model/validations/casted_model.rb

@@ -6,7 +6,7 @@ module CouchRest
         def validate_each(document, attribute, value)
           values = value.is_a?(Array) ? value : [value]
           return if values.collect {|doc| doc.nil? || doc.valid? }.all?
-          document.errors.add(attribute, :invalid, :default => options[:message], :value => value)
+          document.errors.add(attribute, :invalid, :message => options[:message], :value => value)
         end
       end
     end

spec/couchrest/casted_model_spec.rb

@@ -284,6 +284,11 @@ describe CouchRest::Model::CastedModel do
         @toy2.errors.should be_empty
         @toy3.errors.should_not be_empty
       end
+
+      it "should not use dperecated ActiveModel options" do
+        ActiveSupport::Deprecation.should_not_receive(:warn)
+        @cat.should_not be_valid
+      end
     end
 
     describe "on a casted model property" do