Allow dnsmasq to be run as root

Without this change, the dnsmasq command returns an error every time it is called and the nameserver never comes up. This is the error:
dnsmasq: setting capabilities failed: Operation not permitted

This link may have more information about why this change is now necessary:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514214

Also, the syntax for docker tag has changed.