- remove rubygem pointers; I have yanked every version of logstash from   rubygems.org so there is no need to include 'gem install' directions.
- remove rubygem pointers; I have yanked every version of logstash from
  rubygems.org so there is no need to include 'gem install' directions.

  Context:
    * https://gist.github.com/1720432
    * https://gist.github.com/1720739

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