ember-cli 2.12 argument parsing

Original Issue: ember-cli/ember-exam#84

Something has changed in the way that ember-cli parses arguments, I just wanted to add this here for visibility.

DEBUG=ember-cli:* ember exam:iterate 2 --options "--reporter teamcity --random"

Output on 2.11.1

Wed, 19 Apr 2017 19:06:57 GMT ember-cli:cli command: exam:iterate
Wed, 19 Apr 2017 19:06:57 GMT ember-cli:testing cli: command.validateAndRun
Building app for test iterations.
cleaning up...

Output on 2.12.0-beta.1

Wed, 19 Apr 2017 19:11:12 GMT ember-cli:command [lookup-command#3] initialize: name: exam:iterate, name: %s
Wed, 19 Apr 2017 19:11:12 GMT ember-cli:platform-checker: [platform-checker#253] { version: 'v7.9.0', isValid: true, isTested: true, isDeprecated: false }
Wed, 19 Apr 2017 19:11:12 GMT ember-cli:cli command: exam:iterate
Wed, 19 Apr 2017 19:11:12 GMT ember-cli:testing cli: command.beforeRun
Wed, 19 Apr 2017 19:11:12 GMT ember-cli:testing cli: command.validateAndRun
The option '--reporter teamcity --random' is not registered with the exam:iterate command. Run `ember exam:iterate --help` for a list of supported options.

Building app for test iterations.