Fix multiple_carrierwave field spec failing due to mocking

Author: mshibuya

spec/dummy_app/app/mongoid/field_test.rb

@@ -65,7 +65,7 @@ class FieldTest
   mount_uploader :carrierwave_asset, CarrierwaveUploader
   # carrierwave-mongoid does not support mount_uploaders yet:
   #   https://github.com/carrierwaveuploader/carrierwave-mongoid/issues/138
-  mount_uploader :carrierwave_assets, CarrierwaveUploader
+  mount_uploaders :carrierwave_assets, CarrierwaveUploader
 
   validates :short_text, length: {maximum: 255}
 end

spec/rails_admin/config/fields/types/multiple_carrierwave_spec.rb

@@ -8,7 +8,6 @@
 
   describe '#thumb_method' do
     before do
-      allow_any_instance_of(CarrierwaveUploader).to receive(:cache!)
       RailsAdmin.config FieldTest do
         field :carrierwave_assets, :multiple_carrierwave
       end