This is specifically for A records and Junos. Similar things can be done for
other vendors and other record types. For this script, you would need
a separate script for each device. In a future version that I will be
releasing on GitHub, it will take into account all devices and zones.
To use the script, you need the zonefile and junos-ez-stdlib gems.
This script will rewrite your zone file. You are keeping your zone files in
source control, right? It will not restart bind, so the changes will not
go into effect until you manually restart bind. This is a safety feature.