* remove squad support and switch to using pipelines only in RulesBuilder
* remove spawn_food.standard from legacy ruleset definitions
* bugfix: Royale map generates Standard food
* add maps support to CLI
* add automated tests for all registered GameMap implementations
* update README
* reorganize code
* first draft of map generator interfaces
* add explicit random interface to board helpers
* implement standard map
* rename Generator to GameMap
* allow initializing snakes separately from placing them
* add random number generator to Settings
* updates to GameMap interface
* add helpers for creating and updating BoardState with maps