game_settings: Show Blind Spy Reverser variant in Avalon
set_game_settings: Always show roles
set_game_settings: reversers are roles, not variants
Implement Spy Rogue

Closes #32
Merge branch 'spy_rogue'

* spy_rogue:
  Implement Spy Rogue
  set_game_settings: reversers are roles, not variants
  set_game_settings: Always show roles
  game_settings: Show Blind Spy Reverser variant in Avalon