Release 0.1.31

Improvements

upgrade aws-iam-authenticator to version 0.4.0 (#754):
- old kubeconfig files may need updating - you may find eksctl utils write-kubeconfig handy
- macOS: homebrew/core/aws-iam-authenticator is used from now on
API version v1alpha5
- Move SSH parameters under ssh; public keys can now be specified by local file, uploaded key in EC2 or by the key content (see examples/07-ssh-keys.yaml for detailed usage) (#673, #713)
- rename preBootstrapCommand option in the config file has been renamed to preBootstrapCommands (#726)
- --dry-run=false CLI argument has been renamed to --approve (#727)
add support to attach target groups to node groups via ARNs (#746)
add support for using config files in the drain command (#741)
add support for using config files in the command for deleting node groups (#714)
start using new alpha.eksctl.io/ tag prefix (instead of eksctl.cluster.k8s.io/v1alpha1/) (#728)
ensure ami: auto (--node-ami=auto) searches official Amazon and Ubuntu AMIs by owner ID, to avoid security issue (#733)