Make a list of variants that either base or avalon could use
Game: remove check_game_state

It's not used (ResistanceGame has a separate check_game_state that is
unrelated, and also has its own status function)
status: Include status for Trapper
Add format_mission_results

This catches a subtle bug: !missions won't show how many fails on the
4th mission in a 7+ player game
get_loyalty_info: always show roles

It will soon be possible for Base games to have roles, and it does no
harm to use the same code here.
tell_loyalty_to: Always check specific role even in Base games

We will soon have Base games with roles and this will help.
Implement Reversers

Closes #24
who_spies: Always show all roles

Base games have roles now.
start_game: Check that we have enough players

Fixes #28
Merge pull request #27 from an1itdp01y/statusfix

Include status for Trapper
Merge pull request #30 from an1itdp01y/reverser

Reverser
Merge pull request #31 from an1itdp01y/rolecheck

start_game: Check that we have enough players