Allow a minion to request revocation of its own key

def revoke_auth(self, load):
        '''
        Allow a minion to request revocation of its own key
        '''
        if 'id' not in load:
            return False
        keyapi = salt.key.Key(self.opts)
        keyapi.delete_key(load['id'],
                          preserve_minions=load.get('preserve_minion_cache',
                                                         False))
        return True