The dnsutils and jessie-dnsutils images are installing dnsmasq,
which is required for a few tests checking custom DNS servers and
configurations.
dnsmasq is a Linux specific binary. In order for the tests to also
pass on Windows, this commit adds CoreDNS to the images, so a later
commit will update the tests to use CoreDNS instead of dnsmasq.
- Remove debian-security for a couple of arch(es) as they are not
available in the debian repos
- Also fix up the unbound SED problem with push() method
Change-Id: Ibb14ead9581954b66b39c02bcefb5adaa2464fab