[travis] Consume image built with headless JDK
[travis] Consume image built with headless JDK

This image is a little bit smaller, so should download marginally
faster. It will also help assure we don't take dependencies of libraries
that need an X server.
jdubrule/bond,jdubrule/bond,sapek/bond,Microsoft/bond,chwarr/bond,Microsoft/bond,Microsoft/bond,sapek/bond,chwarr/bond,jdubrule/bond,sapek/bond,Microsoft/bond,chwarr/bond,jdubrule/bond,jdubrule/bond,sapek/bond,Microsoft/bond,chwarr/bond,Microsoft/bond,chwarr/bond,jdubrule/bond,sapek/bond,chwarr/bond,sapek/bond