Short-Circuit Manifest Application / Pod Health Checks if not provided

[MMartyn]

If no manifests are provided we could skip the attempt to apply them. Same for the pod health checks.

[MMartyn]

Possibly something like so:

https://github.com/mumoshu/terraform-provider-eksctl/blob/master/pkg/resource/cluster/cluster.go#L40

if len(cluster.CheckPodsReadinessConfigs) == 0 {
  return nil
}

https://github.com/mumoshu/terraform-provider-eksctl/blob/master/pkg/resource/cluster/cluster.go#L93

if len(cluster.Manifests) == 0 {
  return nil
}

[mumoshu]

@MMartyn Thanks! That makes senes. It's fixed in master now.