travis-ci: jdk hostname buffer overflow workaround
travis-ci: jdk hostname buffer overflow workaround

enable travis hostname add-on with short hostname to avoid
jdk getHostName() buffer overflow errors during build:

https://docs.travis-ci.com/user/hostname
https://github.com/travis-ci/travis-ci/issues/5227

rnathanday/dryad-repo,rnathanday/dryad-repo,rnathanday/dryad-repo,rnathanday/dryad-repo,rnathanday/dryad-repo,rnathanday/dryad-repo