* feature(nyz): add trueskill as league metric, naive elo calculator, fix game_env info bug

* fix(nyz): fix league player mutate bug

* fix(nyz): fix league unittest bug

* feature(nyz): add elo ranking in league metric env

* polish(nyz): modify fixed eval policy and trueskill init

* feature(nyz): add init main player in evaluation and fix stop_value bug

* style(nyz): rename test_league_metric to avoid pyc cache bug

* feature(nyz): add naive 1v1 two player demo

* feature(nyz): add 1v1 evaluator and 2 rule-based policy for evaluation

* feature(nyz): modify game env and adjust hyper-param

* feature(nyz): add naive league training multi player demo

* feature(nyz): enable force snapshot to support init historical league player; finish league demo basic code

* feature(nyz): modify selfplay demo and add two type game env

* style(nyz): correct format style

* polish(nyz): correct format style and adapt league demo main

* feature(nyz): add league payoff viz and enable payoff update in league demo

* feature(nyz): modify win rate calculation with draws

* test(nyz): fix one vs one league test compatibility bug

* test(nyz): add selfplay and league demo into unittest and algotest

* style(nyz): correct format

* hotfix(nyz): fix ppo continuous comatibility bug

* refactor(nyz): refactor read_config to 3 different function interface

* feature(nyz): enable env_setting param in entry

* polish(nyz): remove redundant code and global declaration

* polish(nyz): remove flag in import_helper

* polish(nyz): remove unused import

* style(nyz): correct format