Adapter for Redis via Redix. Requires the optional :redix dependency.
cache_1: {Shardex.Adapter.Redix, host: "redis-1", port: 6379, pool_size: 4}All options except :pool_size are passed to Redix.start_link/1.
run/2 calls fun with a connection name, picked at random when
pool_size > 1:
MyApp.Shards.run(key, &Redix.command(&1, ["GET", key]))