Changed image build scripts to install and configure
DAOS v2.0.

Image family name now includes OS. (Ex. daos-server-centos7)

Changed IO500 install script to install IO500 SC21.

Updated terraform/examples/io500 to use new os image family
names and run IO500 SC21.

Refactored env variable names to be more obvious about what
they are used for.

Signed-off-by: Mark A. Olson <mark.a.olson@intel.com>

Accidentally checked the file in with user specific info.
This change corrects that.

Signed-off-by: Mark A. Olson <mark.a.olson@intel.com>

Set the default disk count for the DAOS server configuration
back to 8.

Signed-off-by: Mark A. Olson <mark.a.olson@intel.com>

Image names and image family now include the name of the source image.

Signed-off-by: Mark A. Olson <mark.a.olson@intel.com>

No longer installing IO500 in client images.
mpifileutils and IO500 SC21 will now be installed prior
to running the IO500 benchmark.

The cleanup step that runs before an IO500 run will now
set nr_hugepages in daos_server.yml

Logging improvements.

Signed-off-by: Mark A. Olson <mark.a.olson@intel.com>