Code review comment for ~msaikia/cloud-init:topic-msaikia-vmware-custom-script

Thanks for the patch Chad.
Working on the tests now.
But I have a little concern about putting the marker file in /var/lib/cloud.
What if someone cleans up the entire /var/lib/cloud?
In that case, we will lose the marker file for the next run, and as such will
go through the entire workflow, which is not what we expect. Is there any way to handle that?