Move models and serializers in test to fixtures.rb file

test/unit/active_model/serializer/scope_test.rb

@@ -4,19 +4,6 @@ require 'newbase/active_model/serializer'
 module ActiveModel
   class Serializer
     class ScopeTest < ActiveModel::TestCase
-      class Model
-        def initialize(hash={})
-          @attributes = hash
-        end
-
-        def read_attribute_for_serialization(name)
-          @attributes[name]
-        end
-      end
-
-      class ModelSerializer < ActiveModel::Serializer
-      end
-
       def setup
         @serializer = ModelSerializer.new(nil, scope: current_user)
       end