Jobs will look for bindep.txt in each repo to get a list of required
system packages to be installed. If that file is not found, it will
fallback to a generic bindep.txt file that contains many things that
are not needed for running oslo.utils jobs (things such as mysql and
postgres packages).
This adds a basic bindep.txt file with just a few packages to speed
up job setup times and prevent unnecessary work in the gate.
Change-Id: I7afa363b41b42f7dbd1e31a68b65f122eeffc447