Update TF core to 0.13+ and AWS provider to 3.x

[lizkrznarich]

There's a dependency issue with Terraform AWS ALB module 5.14+, which is incompatible with Terraform core 0.12 despite its docs saying otherwise. Our current AWS provider module (2.7), however, is not compatible with Terraform core 0.13.

Issues notes here:
https://githubmemory.com/repo/terraform-aws-modules/terraform-aws-alb/issues/195

Issue was temporarily solved by setting alb module versions to 5.13.0 https://github.com/ror-community/new-deployment/blob/master/ror/vpc/alb.tf#L3

Eventually, we need to update the AWS provider to 3.x in order to update Terraform core to 0.13+.