refactor code base

[lexruee]

Todo's:

• Reimplement the CLIs using click
• Enhance drivers api for retrieving sensor data.
• Refactor the overall code base.
• Make things easier to test.
• Add missing tests and improve existing tests.

Future Ideas:

• Implement an event-based core using asyncio.
• Implement a plugin system to plugin services like a web service, mqtt publisher, etc.
• Refactor drivers to support an event-based api.