handle apt-get configuration file replacement prompt

On Ubuntu images, apt-get can interactively prompt when package configuration files are being overwritten, which will completely break a provision.

One potential solution is to allow for specifying dpkg options per https://raphaelhertzog.com/2010/09/21/debian-conffile-configuration-file-managed-by-dpkg/, on the initial apt-get upgrade performed by coopr packages. --force-confnew should be an appropriate default. Note that this still may not cover all subsequent package installations, in which case we would need to similarly modify the chef package resources