Refactor networking and commands

This patch refactors the socket management
to use select, as well as refactor all of the
commands into a COMMAND_ENVELOPE dictionary.

This patch also adds the Dockerfile and
docker-compose.yml files

.github/workflows/python.yml

@@ -1,6 +1,6 @@
 name: python
 
-on: [push]
+on: [push, pull_request]
 
 jobs:
   tox: