Issue #748: support for Vagrant >= 1.3.0

- since Vagrant 1.3.0 the removed options are no longer available
- see https://github.com/mitchellh/vagrant/blob/master/CHANGELOG.md#130-september-5-2013
Merge pull request #28 from darxriggs/vagrant-1.3.0-support

Issue #748: support for Vagrant >= 1.3.0