Command expansion doesn't work properly.

```
dan@my-deploy-server-01:~$ rollout foo
rollout -h apps --parallel=100 --timeout=60 -d foo -r all
```

In this case, if I try to run the expanded command, it fails with:

```
usage: rollout
               {foo,bar,baz}
rollout: error: argument profile: invalid choice: 'apps' (choose from 'foo','bar','baz')
```