apollo-server-cache-redis: Add redis connection uri interface to RedisCache

[airtoxin]

RedisCache currently only accept RedisOptions interface of ioredis, but Redis constructor of ioredis can accept more variadic arguments.
https://github.com/luin/ioredis#connect-to-redis

new (port?: number, host?: string, options?: IORedis.RedisOptions): IORedis.Redis;
new (host?: string, options?: IORedis.RedisOptions): IORedis.Redis;
new (options?: IORedis.RedisOptions): IORedis.Redis;

In my use case, my application already connect to redis via connection uri redis://..., and RedisCache also want to connect its redis, but RedisCache can't accept connection uri.

[glasser]

Hi! Rather than continuing down the road of making our package's API even more tightly coupled to the constructor API of ioredis, I'd rather see us expect the user to construct their own ioredis object and pass it to us. #4871 is a start at implementing this but as mentioned in my comment there the API is a bit awkward. I'm not sure that the original author on that PR is interested in continuing on it so somebody else might want to take a shot at it.

[glasser]

I've released a prerelease with this fix (apollo-server-cache-redis@1.4.0-alpha.0, part of the Apollo Server 2.23.0 release). Try out the alpha and see if it works for you! Please provide any feedback in #5094.

[glasser]

This has been released in apollo-server-cache-redis@1.4.0.