Implement a custom HystrixPropertiesStrategy plugin

Add a custom HystrixPropertiesStrategy implementation where getCommandPropertiesCacheKey is overridden to return null so that HystrixPropertiesFactory will always generate a new HystrixCommandProperties for each new HystrixCommand instantiation.
Hmm, builder is not a case class and `hashCode` for the builder is not overridden to be based on the values of the builder, meaning we get new hashCodes for every single newly instantiated builder..