Develop an approach to determining that all the events that have been sent to Micro have been processed

[yalisassoon]

When writing tests against Micro, there is often a need to ensure that Micro has finished processing the events before checking the API to see that they processed successfully. Today, this might be accomplished using sleeps. Might there be some way to get Micro to indicate that it has finished performing a test so that that notification could trigger the completion of the tests?

One idea is to enable an optional parameter sent with an event to Micro, that specifies an endpoint and a map of parameters. Once that event is processed Micro pings that endpoint with those parameters.

Hat tip @benjben @colmsnowplow @jamessnowplow