Change az parameter to preferred_cache_cluster_azs

[odie5533]

https://github.com/cloudposse/terraform-aws-elasticache-redis/issues/173

what

The module should use preferred_cache_cluster_azs in the aws_elasticache_replication_group.

why

This would allow us to specify the preferred primary node. Also the parameter used for AZs, availability_zones, is deprecated.

references

https://github.com/cloudposse/terraform-aws-elasticache-redis/issues/173

[smelchior]

@odie5533 could you update the pull request :)? As the tf aws provider in 5.0.0 now removed the availability_zones option the module currently breaks with that version, so it would be nice to update this.

[odie5533]

@odie5533 could you update the pull request :)? As the tf aws provider in 5.0.0 now removed the availability_zones option the module currently breaks with that version, so it would be nice to update this.

Rebased off the new changes 👍

[rajatrj16]

This is a breaking change - pls merge this.

[milldr]

already merged with #198