Upgrade to terraform 0.12 (#394)

* run terraform upgrade tool

* fix post upgrade TODOs

* use strict typing for variables

* upgrade examples, point them at VPC module tf 0.12 PR

* remove unnecessary `coalesce()` calls

coalesce(lookup(map, key, ""), default) -> lookup(map, key, default)

* Fix autoscaling_enabled broken (#1)

* always set a value for tags, fix coalescelist calls

* always set a value for these tags

* fix tag value

* fix tag value

* default element available

* added default value

* added a general default

without this default - TF is throwing an error when running a destroy

* Fix CI

* Change vpc module back to `terraform-aws-modules/vpc/aws` in example

* Update CHANGELOG.md

* Change type of variable `cluster_log_retention_in_days` to number

* Remove `xx_count` variables

* Actual lists instead of strings with commas

* Remove `xx_count` variable from docs

* Replace element with list indexing

* Change variable `worker_group_tags` to a attribute of worker_group

* Fix workers_launch_template_mixed tags

* Change override_instance_type_x variables to list.

* Update CHANGELOG.md

examples/basic/variables.tf

@@ -4,7 +4,7 @@ variable "region" {
 
 variable "map_accounts" {
   description = "Additional AWS account numbers to add to the aws-auth configmap."
-  type        = "list"
+  type        = list(string)
 
   default = [
     "777777777777",
@@ -12,15 +12,9 @@ variable "map_accounts" {
   ]
 }
 
-variable "map_accounts_count" {
-  description = "The count of accounts in the map_accounts list."
-  type        = "string"
-  default     = 2
-}
-
 variable "map_roles" {
   description = "Additional IAM roles to add to the aws-auth configmap."
-  type        = "list"
+  type        = list(map(string))
 
   default = [
     {
@@ -31,15 +25,9 @@ variable "map_roles" {
   ]
 }
 
-variable "map_roles_count" {
-  description = "The count of roles in the map_roles list."
-  type        = "string"
-  default     = 1
-}
-
 variable "map_users" {
   description = "Additional IAM users to add to the aws-auth configmap."
-  type        = "list"
+  type        = list(map(string))
 
   default = [
     {
@@ -54,9 +42,3 @@ variable "map_users" {
     },
   ]
 }
-
-variable "map_users_count" {
-  description = "The count of roles in the map_users list."
-  type        = "string"
-  default     = 2
-}