WIP: Modifying iframe_sample_app to send and receive messages

:construction: Earlier the iframe_sample_app used to display content from an external website (Wikipedia).

/cc @zendesk/quokka 

### References
- Issue #59

### Risks
 - None
`data.awesome` was just to demonstrate the ability to pass data around, since we're already using `data.message` below we can probably get it of `data.awesome` everywhere else.