Parallelize using asyncio

[nikitaborisov]

You're going to spend a lot of time in the client waiting for things, especially timeouts. On the HTTP side, you can rewrite this using asyncio and aiohttp to replace requests. You have to figure out how to match the right request to the right circuit in stem, though, not sure how to best do it.

[nikitaborisov]

You'll also need this: https://github.com/romis2012/aiohttp-socks