Promotes an arena team member to team captain. Only has effect if the player is captain of the given team.
Signature:
Code
ArenaTeamSetLeaderByName(team, "name")
Arguments:
team - Index of one of the player's arena teams (number, arenaTeamID)
name - Name of a team member to promote (string)
This function does not prompt the user for confirmation before its results take effect -- that behavior is provided by the default UI, and this function is called from the confirmation dialog
