Currently we run Redis unit tests using an "embedded" Redis which is a Java re-implementation of Redis. Problems:
- it covers only a subset of the Redis functionality, in particular it doesn't cover pubsub,
- it's a re-implementation so potentially has different behavior than a real Redis,
- the library providing it, nosql-unit, has removed the embedded Redis code from the latest versions (https://github.com/lordofthejars/nosql-unit/commit/49b7c155c30b3127c31c275d769d622ec16d95ce).
All this means that we must run unit tests agains a real Redis instance.