Remove-node-from-Fuel-inventory check

Pre-condition for case 1:
System test successfully passed - master node was deployed env ready (group deploy_ha)
Case 1 - check node deletion
1. Сheck list of entries of Cobbler test node (node-1) - should be present
2. Change status of test node (node-1) on offline (eth0 down)
3. Delete node from database: #fuel --node 1 --remove-from-db --force
4. Check list of nodes via cli - test node(node-1) should not be present.
5. Check list of entries of Cobbler #dockerctl shell cobbler bash -c "cobbler list" | grep "node-1"

Pre-condition for case 2:
System test successfully passed - master node was deployed env ready (group deploy_ha)
Case 1 - check cluster deletion
1. Delete cluster via cli
2. Check the list of clusters into postgres database:
database: nailgun, table: clusters