Usage
fbGetBusinessManagersUsers(
business_ids = getOption("rfacebookstat.business_id"),
user_types = c('business_users',
'system_users',
'pending_users'),
api_version = getOption("rfacebookstat.api_version"),
username = getOption("rfacebookstat.username"),
token_path = fbTokenPath(),
access_token = getOption("rfacebookstat.access_token"))