Redis Enterprise integration fails when DB is sharded

Current Behaviour

When following the documentation to integrate 3scale with a sharded Redis Enterprise instance an error is logged and the integration does not work as expected as a result.

4bundler: failed to load command: bin/3scale_backend_worker (bin/3scale_backend_worker)
5/opt/ruby/deps/rubygems/github.com/3scale/redis-rb/redis-rb-external-gitcommit-7210a9d6cf733fe5a1ad0dd20f5f613167743810/app/lib/redis/client.rb:126:in `call': CROSSSLOT Keys in request don't hash to the same slot (context='', command='blpop', original-slot='8016', wrong-slot='6971', first-key='resque:queue:priority', violating-key='resque:queue:main') (Redis::CommandError)

Expected behaviour

Following the documentation should result in no errors and a successful integration.

Additional note: Redis documentation suggests that multiple key operations need to follow certain conventions to work so we "force" those keys to be part of the same hash slot, if we do not do this then I think the error message logged is expected and we need to fix this.