[PROPOSAL] modify devcloud storage setup

[Marcus Sorensen]

In running integration tests, I noticed that the volume tests fail because
there are shared and local compute/disk offerings. I propose that we add to
devcloud an /opt/storage/primarynfs directory, shared out in /etc/exports,
and we change the devcloud config to add this primary storage in.
Optionally, we can change the default tags to use local storage for
efficiency in other things, but this way there is both a local and a shared
storage type for the tests to succeed.