#documentation
- https://dev.acquia.com/blog/use-drush-upgrade-drupal-6-drupal-7
- https://www.drupal.org/project/drush_sup
- http://cgit.drupalcode.org/drush_sup/tree/README.txt?id=refs/heads;id2=7.x-2.x
- http://www.drupaldump.com/migrating-drupal-6-drupal-7-drush-sup-site-upgrade
ubercart migration