test: k8s: delete pv and pvc at teardown.

Delete the persistent volume and persistent volume claim
on teardown() to have the system clean after running the
test.

Signed-off-by: Salvador Fuentes <salvador.fuentes@intel.com>

Author: chavafg

integration/kubernetes/k8s-volume.bats

@@ -55,5 +55,7 @@ setup() {
 
 teardown() {
 	sudo -E kubectl delete pod "$pod_name"
+	sudo -E kubectl delete pvc "$volume_claim"
+	sudo -E kubectl delete pv "$volume_name"
 	sudo rm -rf $tmp_file
 }