authdns config/CI refactor [2/5]
Create the new top-level "config" file in the repo, create
utils/mock_etc for mocking the puppet-defined files for CI
testing, and use the new symlinked path in /etc/geoip for the
database file location in our geo-maps file.
Bug: T205439
Change-Id: Ic475adfe29f31d1f9fc84f5be74dddecb815c42a