code: def delete_vapp(vAppId)
        params = {
          'method' => :delete,
          'command' => "/vApp/vapp-#{vAppId}"
        }
  
        response, headers = send_request(params)
        task_id = headers[:location].gsub(/.*\/task\//, "")
        task_id
      end
docs: Delete a given vapp
   NOTE: It doesn't verify that the vapp is shutdown