Update to use apache-libcloud 0.15.1

Update the import-aws module to be able to use the latest version of apache-libcloud (0.15.1 as of this commit).
- Update instance variables for Node to match latest version
- Append Node.id to Node.name in order to generate unique host names
Merge pull request #8 from monkey1016/update-libcloud-latest

Update to use apache-libcloud 0.15.1