Migration to `trio`

This issue serves as a starting point to discuss migrating from asyncio to trio.

trio builds upon the insight gained from use of asyncio across the Python ecosystem; in particular, it provides support for a structured approach to concurrency that enables the correct construction of large asynchronous programs.

A simple migration is to just replace use of asyncio with the use of trio.

A more complex, but possibly more useful path is to consider how we can abstract out the use of IO in py-libp2p so that a client of the library can supply their own IO. Refer to this https://sans-io.readthedocs.io/ for more information on what I’m thinking here.

[ralexstokes]

Also worth considering using this: https://github.com/python-trio/trio-asyncio

[pipermerriam]

@ShadowJonathan we are 👍 to going this direction, but we may take a bit of a pragmatic first step towards getting it working with trio first since full io abstraction is a more complex piece of work and is likely to take more thought and effort. At present this library is primarily used in trinity codebase and the two are being developed together.

I suspect this is something that we’ll entertain focusing on in the 6-12 month timeline.