Managing DNS for subdomains not possible.

[mklauber]

Based on the code at https://github.com/theforeman/smart_proxy_dns_route53/blob/master/lib/smart_proxy_dns_route53/dns_route53_main.rb#L80, it appears that the hosted zone is assumed to contain two segments. This makes it impossible to use the route53 smart proxy to manage a hosted zone with the domain internal.example.com.