Should we support async and await?

While experimenting with the new features in Python 3.7 for #257, I found that `async` and `await` messed up the live coding display, because multiple function calls can get interspersed. See the comments on that issue for detailed examples.

However, is it even helpful to use live coding for asynchronous code? I'm going to wait until I have more experience with it or I hear from users. I wonder if generating some version of a sequence diagram would be more useful.

Brett Cannon wrote a good [introduction] to `async` and `await`.

[introduction]: https://snarky.ca/how-the-heck-does-async-await-work-in-python-3-5/

Start by reading issue #257 and the linked introduction to Python async/await. Determine whether live coding can represent interspersed asynchronous calls or whether sequence diagrams would be more useful. Done is not defined in this issue, so the scope and acceptance criteria need agreement first.

Written by the indexing model from the issue text.