Since some of these data are generated within TokenDao (e.g. the timestamp),
the caller cannot infer all values.
* src/server/token/MongoTokenDao.ts (updateToken): Return
Promise<{void=>TokenData}>.
* src/server/token/TokenDao.ts (TokenDao)[#updateToken]: Update interface
accordingly.
* test/server/token/MongoTokenDaoTest.ts: Update test accordingly.