Implement Dockerfile and CI/CD to DockerHub

[EONRaider]

This PR adds a Dockerfile to clairvoyance with the following considerations:

• Adds deterministic base images for reproducible builds.
• Adds a multi-stage build that keeps the image size at about 60MB in size.
• Adds a least-privileged user in compliance with Docker security best practices.

We also have a workflow with a CICD pipeline to DockerHub. All you need to do is to add the DOCKER_HUB_USERNAME and DOCKER_HUB_ACCESS_TOKEN secrets to the repository and all pushes/merges to the master branch will automatically push an image to DockerHub.

This is a nice tool but I needed to run it from a Docker container, so here is my contribution. If you merge I'll go ahead later and add a few installation instructions for Docker to the README.md file.

[nikitastupin]

This is a cool feature! Thank you very much 😃

I've just changed an event that triggers an image publishing to Docker Hub at 928ee90 so it publishes an image only if tests finished successfully.

[nikitastupin]

The image should be pullable from https://hub.docker.com/r/nikitastupin/clairvoyance

[EONRaider]

Great! I'll add some simple instructions on how to use it with Docker to the README.md file and do a new PR.