we should specify nginx as nginx-light or it will conflict o nginx-full from swift with message like
Package nginx is a virtual package provided by:
  nginx-full 1.2.7-0ubuntu0ppa1~precise
  nginx-light 1.2.7-0ubuntu0ppa1~precise
Merge pull request #1777 from MirantisDellCrowbar/feature/pfs/betty/grizzly

https://github.com/crowbar/crowbar/pull/1777

Merged by devtool for VictorLowther