generate_kvs_id
* Generates a new unused kvs_id
*
* @param kvs_id [out] A new unused kvs_id
* @param [in]
* @param [in]
*
* @returns 0 if successful, -1 if not.
*
* @note Due to race conditions the kvs_id might be in use right after this call
* First version just returns a random kvs_id
*/
int generate_kvs_id(struct mio_kvs_id *kvs_id);```