Support explicit pausing httpClient

[ndkhaivn]

I have some test scenarios where the clients need to wait for an amount of time before resetting back to the first request. Would this feature be valid?

At the moment falsy return from setupRequest() will only reset the requestIterator but there's no option to explicitly pause the client.

Can we have a sort of return from setupRequest() to tell the client to pause for a while before moving to the next request?

[mcollina]

Sure it would be valid! Would you like to send a PR?

[ndkhaivn]

Working on it xD