Move to python

The JS implementation of webtorrent actually doesn't WebRTC and just uses a headless chromium instance. Unfortunately, it doesn't work, so an alternative was found in libtorrent.

Once again, unfortunately, libtorrent is C++ and requires building, so instead of fighting with that, a docker image is used that has libtorrent already built and ready for python. That's also necessary since libtorrent (at the time of writing this) only has support for webtorrent in its master branch.