* Problem: Source files contain no license info
Solution: Add comments with SPDX license info to source files
* Python 3 files don't need # -*- coding: utf-8 -*-
* Replace double quotes with single quotes (flake8)
* Test event subscriber to tendermint via ws
* Problem: Tendermint is not part of stack for CI
Solution: Add Tendermint to stack for CI. For simplicity's sake
docker-compose is being used.