Remove assumption (#779)

* Remove assumption

This is not needed since 8.0.0 right?

* Update CHANGELOG.md

Co-authored-by: Thierno IB. BARRY <ibrahima.br@gmail.com>

CHANGELOG.md

@@ -9,6 +9,7 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [[v9.?.?](https://github.com/terraform-aws-modules/terraform-aws-eks/compare/v9.0.0...HEAD)] - 2020-xx-xx]
 
+- Remove obsolete assumption from README (kubectl & aws-iam-authenticator) (by @pierresteiner)
 - Ensuring that ami lookup hierarchy is worker_group_launch_templates and worker_groups -> worker_group_defaults -> and finally aws ami lookup (by @ck3mp3r)
 - Fix doc about spot instances, cluster-autoscaler should be scheduled on normal instances instead of spot (by @simowaer)
 - Adding `encrypted` option to worker's root_block_device as read from the worker configurations (by @craig-rueda)

README.md

@@ -14,7 +14,6 @@ Read the [AWS docs on EKS to get connected to the k8s dashboard](https://docs.aw
 * You want to create an EKS cluster and an autoscaling group of workers for the cluster.
 * You want these resources to exist within security groups that allow communication and coordination. These can be user provided or created within the module.
 * You've created a Virtual Private Cloud (VPC) and subnets where you intend to put the EKS resources. The VPC satisfies [EKS requirements](https://docs.aws.amazon.com/eks/latest/userguide/network_reqs.html).
-* If `manage_aws_auth = true`, it's required that both [`kubectl`](https://kubernetes.io/docs/tasks/tools/install-kubectl/#install-kubectl) (>=1.10) and [`aws-iam-authenticator`](https://github.com/kubernetes-sigs/aws-iam-authenticator#4-set-up-kubectl-to-use-authentication-tokens-provided-by-aws-iam-authenticator-for-kubernetes) are installed and on your shell's PATH.
 
 ## Usage example