Execute a function asynchronously; eauth is respected

        This function requires that :conf_master:`external_auth` is configured
        and the user is authorized

        .. code-block:: python

            >>> wheel.cmd_async({
                'fun': 'key.finger',
                'match': 'jerry',
                'eauth': 'auto',
                'username': 'saltdev',
                'password': 'saltdev',
            })
            {'jid': '20131219224744416681', 'tag': 'salt/wheel/20131219224744416681'}

def cmd_async(self, low):
        '''
        Execute a function asynchronously; eauth is respected

        This function requires that :conf_master:`external_auth` is configured
        and the user is authorized

        .. code-block:: python

            >>> wheel.cmd_async({
                'fun': 'key.finger',
                'match': 'jerry',
                'eauth': 'auto',
                'username': 'saltdev',
                'password': 'saltdev',
            })
            {'jid': '20131219224744416681', 'tag': 'salt/wheel/20131219224744416681'}
        '''
        fun = low.pop('fun')
        return self.asynchronous(fun, low)