AttachISO task creates the user-data/meta-data cloud init files and creates cloud-init.iso file using "genisoimage" tool. It then uploads it to the datastore where the master/worker VM resides and inserts it into the cd-rom device of the master/worker VM. When the master/worker VM powers on, the cloud-init package in it runs the bootstrap script that downloads nodeup and runs it.
Also removed redundant VirtualMachineModelBuilder that does nothing.
Testing done:
1. Tested end to end that the master and worker VMs executes the cloud-init script successfully.
2, "make ci" is successful.