Add duration to RoundRobinQueue

[ruudk]

Tries to fix #319

[henrikbjorn]

I suspect this violates the interface.

[ruudk]

Same as here https://github.com/bernardphp/bernard/blob/master/src/Queue/PersistentQueue.php#L93

[sagikazarmark]

I see two possible options:

• add duration to the interface
• make it a constructor argument

The second one is probably better from the abstraction point of view, but much harder to implement.

BTW that duration argument is never passed anywhere and the default value for drivers is 5 seconds anyway, so what's the point in adding it here now?