Simplify implementation

[JeanMertz]

Some minor tasks I'm doing right now:

• remove unneeded dependencies (or their default features) to improve compile times (Improve compile times #62)
• remove juniper feature flag, as there is no point in disabling that feature
• restructure project to make it easier to find things (similar to how the Tower project is structured
• use GitHub Actions for better/faster/simpler CI implementation
• remove dual license (only use MIT)
• stop publishing internal crates (all processors), and remove their versioning tags
• rename server binary crate to automaat, and have it start either the server or worker(s)
• see how easy it is to migrate to async/await syntax to make the code easier to follow
• ...