* Finished first cut of managed node groups
* Updated formatting and extra fields.
* Updating Changelog and README
* Fixing formatting
* Fixing docs.
* Updating required Version
* Updating changelog
* Adding example for managed node groups
* Managed IAM Roles for Nodegroups now have correct policies. Tags can now be added to node groups.
* Fixing bug where people could set source_security_group_ids without setting ssh key causing a race condition within the aws provider.
* Adding lifecycle create_before_destroy
* Adding random pet names for create_before_destroy
* Updating per comments.
* Updating required versions of terraform
* Updating per comments.
* Updating vars
* Updating minimum version for terraform
* Change worker_groups_managed_node_groups to node_groups
* Using for_each on the random_pet
* Adding changes recommended by @eytanhanig
* Update node_groups.tf
