- bump lumberjack gem version
- bump lumberjack version again.
  This version of lumberjack has a 3x (average) performance increase vs
  the previous implementation in terms of event rates. On my
  workstation, the last release of logstash could do roughly 8000
  events/sec, where this commit peaks at 23000 events/sec
  (with a single lumberjack client connection).