RedisFeatureStore should handle redis outage #67
Description
From my reading of the code and from some limited testing, the LaunchDarkly client gracefully handles unavailability of the LaunchDarkly service.
The RedisFeatureStore does not appear to handle outages gracefully. IMO it should return the default when redis is unavailable. (I discovered the problem when I had my redis URL misconfigured while running in ldd mode.)