PHASE 1 - Add Packet-CI playbook and configuration (#4537)

tests/Makefile

tests/cloud_playbooks/create-packet.yml

tests/cloud_playbooks/delete-packet.yml

tests/cloud_playbooks/roles/packet-ci/defaults/main.yml

tests/cloud_playbooks/roles/packet-ci/tasks/create-vms.yml

tests/cloud_playbooks/roles/packet-ci/tasks/delete-vms.yml

tests/cloud_playbooks/roles/packet-ci/tasks/main.yml

tests/cloud_playbooks/roles/packet-ci/templates/inventory.j2

tests/cloud_playbooks/roles/packet-ci/templates/vm.yml.j2

tests/requirements.txt