Allow making replenishRate float?

[seovchinnikov]

Hello!
In some cases it can be useful to make replenishRate float (special cases when 0<replenishRate< 1). So we will be able for example to increase value in the bucket by values < 1 every second (so value 0.1 means to fulfill bucket with 1 token every 10 seconds).

No code changes has be made for lua script to do this, only for config class.

spring-cloud-gateway/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/ratelimit/RedisRateLimiter.java

Line 318 in 16808fb

private int replenishRate;

[spencergibb]

PRs welcome (including a test).