GUACAMOLE-407: Upgrade Docker image to Ubuntu 17.10.
GUACAMOLE-407: Upgrade Docker image to Ubuntu 17.10.

apache/guacamole-server,glyptodon/guacamole-server,glyptodon/guacamole-server,mike-jumper/incubator-guacamole-server,mike-jumper/incubator-guacamole-server,apache/guacamole-server,mike-jumper/incubator-guacamole-server,mike-jumper/incubator-guacamole-server,apache/guacamole-server,glyptodon/guacamole-server