make bin/logstash a shell script now that we don't use bundler
make bin/logstash a shell script now that we don't use bundler

joekiller/logstash-kafka,joekiller/logstash-kafka,opentable/logstash-kafka,Aloomaio/logstash-kafka,Aloomaio/logstash-kafka,tinglinux/logstash-kafka,tinglinux/logstash-kafka,opentable/logstash-kafka