add ruby-dev package to buildbot_slave module
add ruby-dev package to buildbot_slave module

sebbASF/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,sebbASF/infrastructure-puppet,apache/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,apache/infrastructure-puppet,apache/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,sebbASF/infrastructure-puppet,sebbASF/infrastructure-puppet