Use 'kubeadm reset' instead of replicating it

test/840_weave_kube_3_test.sh

@@ -4,11 +4,7 @@
 
 tear_down_kubeadm() {
     for host in $HOSTS; do
-        # If we don't stop kubelet, it will restart all the containers we're trying to kill
-        run_on $host "sudo systemctl stop kubelet"
-        rm_containers $host $(docker_on $host ps -aq)
-        run_on $host "test ! -d /var/lib/kubelet || sudo find /var/lib/kubelet -execdir findmnt -n -t tmpfs -o TARGET -T {} \; | uniq | xargs -r sudo umount"
-        run_on $host "sudo rm -r -f /etc/kubernetes /var/lib/kubelet /var/lib/etcd /etc/cni /opt/cni/bin/*weave*"
+        run_on $host "sudo kubeadm reset && sudo rm -r -f /opt/cni/bin/*weave*"
     done
 }