(gh-477) enables root for non-root users on ec2 hypervisor

- root login is not possible on ubuntu-amis
- provision is not possible without root

This Patch enables root when the host['user'] differs from "root"
(gh-477) enables root for non-root users on ec2 hypervisor

- fixes codestyle
- fixes tests
Merge pull request #478 from paschdan/awsSdk-nonroot

(gh-477) enables root for non-root users on ec2 hypervisor