Naming alternative for Master role

https://github.com/ailabstw/PIPs/blob/master/PIP-0010.md

In the roles, there are two, master and member. In places with slavery past/present, master means people with ownership and management of slaves. While ptt.ai is not using master-slave terminology, master-member still feels problematic.

Some alternatives include admin, manager, moderator, or steward. Personally, I prefer the latter two, moderator or steward.