Merge pull request #1 from yoolk/liquid_drop_scope_associations

Liquid drop scope associations

Author: chamnap

lib/liquid-rails/drops/collection_drop.rb

@@ -29,9 +29,9 @@ def self.scope(*scope_names)
       delegate :total_count, :total_pages, to: :objects
 
       def initialize(objects, options={})
-        options.assert_valid_keys(:with)
+        options.assert_valid_keys(:with, :scope)
 
-        @objects         = objects
+        @objects         = options[:scope].nil? ? objects : objects.send(options[:scope])
         @drop_class_name = options[:with]
       end