Support should_ask in Echo interaction

[mklaber]

Feature request: conditionally display Echo interactions similar to how BasicQuestion, Confirm, etc. work. This would allow us to display text conditionally based on responses to previous questions.

Confirm you like dogs? [y/N]
y
Great, now that we know you like dogs, here are some things you'll need to know:

• Unlike cats, dogs actually like you
• Unlike cats, dogs don't plot ways to kill you in your sleep

What breed of dog do you prefer? [English Setter]

[plannigan]

That seems like a reasonable request. It could even be added to Acknowledge to make things more symmetrical.