This adds a test that builds the Docker container, tries to run it
and sees whether it can establish a connection to port 9000.
This test should prevent us from breaking the Docker build (again).
It also improves the GitHub action for consistent dependencies (we were mixing requirements.txt and setup.py dependencies) and adds a matrix for testing against Python 3.6, 3.7 and 3.8
This adds a test that builds the Docker container, tries to run it and sees whether it can establish a connection to port 9000. This test should prevent us from breaking the Docker build (again).
It also improves the GitHub action for consistent dependencies (we were mixing requirements.txt and setup.py dependencies) and adds a matrix for testing against Python 3.6, 3.7 and 3.8