Allowed talking to redis sentinel by changing the redis client to ioredis.

[abdoolly]

This pull request is proposed to solve this issue

Problem statement The problem was that the current state of hydra make it very hard for it to work in a high availability environment specifically in talking with redis since the current client that is used does not support redis modes of working in high availability.

Solution So , what this pull request do is that I have changed the main redis client which is node_redis to the more advanced redis client which is ioredis that supports redis cluster mode , and redis redis sentinel. and actually that's all we need to make hydra work in high availability.

change description: The change as said above is just changing the main connection from node_redis to ioredis .I did not to change most of the commands since ioredis have similar api to node_redis I have also used this guide for migrating which shows the difference between both clients.

so the main changes are

• changed the main redis connection
• made new function for handling multi result since it's a bit different also it is backward compatible if we wanted to still use the node_Redis.
• made a new function to handle if we should use .batch if node_Redis and pipeline if ioredis which is the equivalent of .batch in ioredis
• also I have passed the tests so all tests are passing.

Also later on I will be making a small guide to be used on how to install and deploy hydra with redis in high availability environment in kubernetes. Thanks

[abdoolly]

I have made a commit that removed the white spaces and only the main changes are remaining now.