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
Why do we need to check for `data.awesome` presence if it's our own data structure? Perhaps it would be better to send something back in the data structure that we can render.