Change hashes to be strings

[wearhere]

e.g.

redfour/src/index.js

Line 80 in d09fa34

redis.call("HMSET", KEYS[1], "index", index);

Since we only set a single field.

Makes code simpler, probably a small performance improvement too.

[wearhere]

We could also replace PEXPIRE with PSETEX then.