Add an asyncio (dogeweb) implementation.

Long story short, this is an implementation of Notejam that uses [this language](http://pyos.github.io/dg/) and [this web framework](https://github.com/pyos/dogeweb). I hope there is no requirement that says platforms and frameworks have to be at least somewhat popular to make it into this repository. :-)

Note that this implementation is somewhat different from the others; see the README for details. Also, while it should be relatively easy to test in theory, I haven't actually written any tests. (Because I'm really lazy.) Hopefully, that's not a big problem either.