Clear role cache

[rojen11]

Is your feature request related to a problem? Please describe.
Roles are not updated immediately due to cache so it would be nice to have a command that can be used to clear the cache of the bot.

Describe the solution you'd like
The command could be something like ab role --clear-cache.

Describe alternatives you've considered
If there is gonna be a command prefix for mod command then it could be included in that instead of ab role.

Additional context
This command should only be available to a privileged user.