Update develop branch with progress

[bristermitten]

• Update all dependencies and tooling, including actions
• major refactors of internals
• implement basic key-based auth
• add some nice testing with Spock

game flow progress report:

• creating games works
• joining games works
• admins of a game can force a game into warmup phase, which starts a 5s timer, and then moves into in_progress phase
• calls challenges service to pick a random challenge
• starts a round