Missing expiration

[leonardodeoliveira]

I noticed a ever-increasing number of keys in my cluster. It looks like the redis sliding window stats keys are never set to expire

In RedisConcurrencyManager and RedisFixedWindowManager none of the keys have expiration.

I don't think this is expected is it?

[cristipufu]

Yes, we should fix this

[leonardodeoliveira]

@cristipufu thanks for merging the PR. when are you planning to release it?