chore: add Dockerfile + ci image test and DockerHub upload

[AngryMaciek]

Proposed changes ⤴️

Add a Dockerfile + test CI

Fixes #36

Types of changes 🔧

What type of changes does your code introduce to the warlock?

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation updated
• Testing updated
• Codebase refactoring
• Other

Checklist ✅

If you're unsure about any of those below, ask explicitly.
This is simply a reminder of what needs to be checked before merging your code.

• I have read the CONTRIBUTING.
• I have performed a self-review of my own code.
• I have added necessary documentation (if appropriate).
• My changes generate no new warnings.
• I have commented my code, particularly in hard-to-understand areas.