I can confirm it is working here too, using Ubuntu 14.04LTS, and starting openvpn automatically as a service. It also works on 16.04 LTS firing it up with the network-manager GUI, but I don't do that now.
You can use the ISO country code for the hostname for all existing countries. i.e. DE.airvpn.org, NL.airvpn.org, CH.airvpn.org and so on. Your config file should then have an entry like: remote nl.airvpn.org