rate limited in dev, strange values


```
$ redis
127.0.0.1:6379> get limit:::1:count
"-1"
```

based on https://github.com/scttcper/koa-simple-ratelimit I see that it uses a TTL key at redis to accomplish this, however, it looks like it'll never expire

```
$ redis
127.0.0.1:6379> ttl limit:::1:count
(integer) -1
```