Adds check for duffy node provisioning in unittests CI job

[navidshaikh]

Checks if the unittests CI job is able to receive the nodes from duffy, upon failure, print the error message and exit.

Also adds checks for

• package install
• rsync as well.

[navidshaikh]

Nice - duffy failed to provision the node and we have the error message listed as expected. Logs - https://ci.centos.org/job/centos-container-pipeline-service-ci-pr-unittests/153/console

[navidshaikh]

dotests-unittests