Regenerate gemspec for version 0.8.4
Regenerate gemspec for version 0.8.4

iron-io/iron_worker_ruby_ng,iron-io/iron_worker_ruby_ng,iron-io/iron_worker_ruby_ng,iron-io/iron_worker_ruby_ng,iron-io/iron_worker_ruby_ng,iron-io/iron_worker_ruby_ng,iron-io/iron_worker_ruby_ng