Retiring instance does not work

[romanblanco]

I ran into issue while trying to reproduce bug mentioned of review for PR #5410.
Loading data from Openstack provider works fine for me, but after trying to retire Openstack instance, I'm getting error:

[----] I, [2016-02-22T13:33:29.050136 #19788:2b05fa5bd968]  INFO -- : Raising Retirement Event for [cloudformation-spec]
[----] I, [2016-02-22T13:33:29.054524 #19788:2b05fa5bd968]  INFO -- : <AutomationEngine> MiqAeEvent.build_evm_event >> event=<"request_orchestration_stack_retire"> inputs=<{:retirement_initiator=>"system", :orchestration_stack=>#<ManageIQ::Providers::Amazon::CloudManager::OrchestrationStack id: 10000000000010, name: "cloudformation-spec", type: "ManageIQ::Providers::Amazon::CloudManager::Orchest...", description: "AWS CloudFormation Sample Template vpc_single_inst...", status: "CREATE_FAILED", ems_ref: "arn:aws:cloudformation:us-east-1:200278856672:stac...", ancestry: nil, ems_id: 10000000000009, orchestration_template_id: 10000000000001, created_at: "2015-10-22 09:12:49", updated_at: "2015-10-30 13:14:31", retired: false, retires_on: "2015-11-01", retirement_warn: 7, retirement_last_warn: "2015-10-30 13:14:31", retirement_state: nil, retirement_requester: nil, status_reason: "The following resource(s) failed to create: [WebSe...", cloud_tenant_id: nil, resource_group: nil>, :type=>"ManageIQ::Providers::Amazon::CloudManager::OrchestrationStack", "MiqEvent::miq_event"=>10000000285949, :miq_event_id=>10000000285949, "EventStream::event_stream"=>10000000285949, :event_stream_id=>10000000285949}>
[----] E, [2016-02-22T13:33:29.055063 #19788:2b05fa5bd968] ERROR -- : [NoMethodError]: undefined method `tenant_identity' for #<ManageIQ::Providers::Amazon::CloudManager::OrchestrationStack:0x00560bfaab3360>  Method:[rescue in retire_now]
[----] E, [2016-02-22T13:33:29.055241 #19788:2b05fa5bd968] ERROR -- : /home/rblanco/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/activemodel-5.0.0.beta2/lib/active_model/attribute_methods.rb:433:in `method_missing'
/home/rblanco/devel/manageiq/lib/miq_automation_engine/engine/miq_ae_event.rb:114:in `call_automate'
/home/rblanco/devel/manageiq/lib/miq_automation_engine/engine/miq_ae_event.rb:41:in `raise_evm_event'
/home/rblanco/devel/manageiq/app/models/miq_event.rb:43:in `raise_evm_event'
/home/rblanco/devel/manageiq/app/models/mixins/retirement_mixin.rb:168:in `raise_retirement_event'
/home/rblanco/devel/manageiq/app/models/mixins/retirement_mixin.rb:115:in `retire_now'
/home/rblanco/devel/manageiq/app/models/mixins/retirement_mixin.rb:103:in `retirement_check'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/activerecord-5.0.0.beta2/lib/active_record/relation/delegation.rb:39:in `each'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/activerecord-5.0.0.beta2/lib/active_record/relation/delegation.rb:39:in `each'
/home/rblanco/devel/manageiq/app/models/orchestration_stack/retirement_management.rb:13:in `retirement_check'
/home/rblanco/devel/manageiq/app/models/miq_queue.rb:335:in `block in deliver'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/2.2.0/timeout.rb:89:in `block in timeout'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/2.2.0/timeout.rb:34:in `block in catch'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/2.2.0/timeout.rb:34:in `catch'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/2.2.0/timeout.rb:34:in `catch'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/2.2.0/timeout.rb:104:in `timeout'
/home/rblanco/devel/manageiq/app/models/miq_queue.rb:331:in `deliver'
/home/rblanco/devel/manageiq/app/models/miq_queue_worker_base/runner.rb:106:in `deliver_queue_message'
/home/rblanco/devel/manageiq/app/models/miq_queue_worker_base/runner.rb:134:in `deliver_message'
/home/rblanco/devel/manageiq/app/models/miq_queue_worker_base/runner.rb:151:in `block in do_work'
/home/rblanco/devel/manageiq/app/models/miq_queue_worker_base/runner.rb:145:in `loop'
/home/rblanco/devel/manageiq/app/models/miq_queue_worker_base/runner.rb:145:in `do_work'
/home/rblanco/devel/manageiq/app/models/miq_worker/runner.rb:327:in `block in do_work_loop'
/home/rblanco/devel/manageiq/app/models/miq_worker/runner.rb:324:in `loop'
/home/rblanco/devel/manageiq/app/models/miq_worker/runner.rb:324:in `do_work_loop'
/home/rblanco/devel/manageiq/app/models/miq_worker/runner.rb:146:in `run'
/home/rblanco/devel/manageiq/app/models/miq_worker/runner.rb:121:in `start'
/home/rblanco/devel/manageiq/app/models/miq_worker/runner.rb:21:in `start_worker'
/home/rblanco/devel/manageiq/app/models/miq_worker.rb:346:in `block in start'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/nakayoshi_fork-0.0.3/lib/nakayoshi_fork.rb:24:in `fork'
/home/rblanco/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/nakayoshi_fork-0.0.3/lib/nakayoshi_fork.rb:24:in `fork'
/home/rblanco/devel/manageiq/app/models/miq_worker.rb:344:in `start'
/home/rblanco/devel/manageiq/app/models/miq_worker.rb:274:in `start_worker'
/home/rblanco/devel/manageiq/app/models/miq_worker.rb:154:in `block in sync_workers'
/home/rblanco/devel/manageiq/app/models/miq_worker.rb:154:in `times'
/home/rblanco/devel/manageiq/app/models/miq_worker.rb:154:in `sync_workers'
/home/rblanco/devel/manageiq/app/models/miq_server/worker_management/monitor.rb:49:in `block in sync_workers'
/home/rblanco/devel/manageiq/app/models/miq_server/worker_management/monitor.rb:47:in `each'
/home/rblanco/devel/manageiq/app/models/miq_server/worker_management/monitor.rb:47:in `sync_workers'
/home/rblanco/devel/manageiq/app/models/miq_server.rb:186:in `start'
/home/rblanco/devel/manageiq/app/models/miq_server.rb:273:in `start'
/home/rblanco/devel/manageiq/lib/workers/evm_server.rb:60:in `start'
/home/rblanco/devel/manageiq/lib/workers/evm_server.rb:79:in `start'
/home/rblanco/devel/manageiq/lib/workers/bin/evm_server.rb:4:in `<main>'

@Ladas, @blomquisg