fixing error class expectation in test
fixing error class expectation in test

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