Sharepoint 2013 Workflow Custom Activity

Hi,

I need to develop a Custom Action Workflow for SharePoint Designer 2013. I tried use this blog (http://www.sharepointeurope.com/blog/2013/11/25/how-to-create-a-workflow-custom-action-for-sharepoint-designer-2013-using-visual-studio-2013).

But, in example, the author use actions provided by VS 2012, like LookupListItemID. However, I need to create an action for Publishing the major version of document and there aren't actions to publishing documents...

thanks