RethinkDB addon not working on Travis CI

Rethink DB addon is not working, getting following error:

E: There were unauthenticated packages and -y was used without --allow-unauthenticated
Installing RethinkDB default instance configuration
cp: cannot stat ‘/etc/rethinkdb/default.conf.sample’: No such file or directory
Starting RethinkDB v2.3.5
0.01s$ sudo service rethinkdb start
rethinkdb: unrecognized service

You can check build here

See Rethinkdb: command not found ; maybe that solution works for you, if not, add a reply in that thread with any problems you are experiencing.