Honor the 'rest' option

[khepin]

From #529

Looks like we correctly honor all of the other queue:work options and have kept maintaining compatibility with queue:work.
There are also other options from queue:work that we honor despite the fact that they make little sense with this consumer. For example sleep when the queue is empty is useful for queues where you pull the work from the queue. Especially ones like SQS where you get charged every time you make a request. But when doing basic_consume this makes little sense yet it is respected by this package.

Our other choices with this --rest options would be:

1. accept it but ignore it (current situation). Making it the first of the queue:work options we are not compatible with
2. remove it (would break compatibility with queue:work by throwing an exception for providing an undefined option)
3. accept it and output a warning