Fixes #11168: Fix Ubuntu version in getting started guide
Fixes #11168: Fix Ubuntu version in getting started guide

marxarelli/vagrant,gitebra/vagrant,gitebra/vagrant,sni/vagrant,marxarelli/vagrant,chrisroberts/vagrant,gitebra/vagrant,sni/vagrant,mitchellh/vagrant,sni/vagrant,marxarelli/vagrant,chrisroberts/vagrant,mitchellh/vagrant,mitchellh/vagrant,chrisroberts/vagrant,sni/vagrant,gitebra/vagrant,mitchellh/vagrant,chrisroberts/vagrant,marxarelli/vagrant