1. Callback on user input 2. Dynamic value setting for step responses

[pgerlich]

So I'm looking at implementing this, and have gotten almost completely through doing what I want to do.

I do have two feature requests, the later of which I will open a PR for this week.

1. You should be able to provide a callback such as 'onUserInput' which allows the parent component to know what the user is saying. This is necessary if you want your users to have a truly dynamic conversation. For now, I am using the 'validator' to store the value and kick off any actions which may be associated with the user input.

2. Going off of the last point, it is crucial that you can update steps dynamically and that the chatBox accepts new steps and swaps them out for the steps it has in its state, assuming that the new steps pass a 'sanity check'. This would be the second piece in allowing dynamic conversations, thereby allowing the user to drive the discussion, rather than having a pre-planned interaction which has limited uses.

There is probably an alternative to the second case, but that seems like the best option right now. Bear in mind I just picked this code up today.

Thanks!