To make an ISO to attach to the vSphere VM, run from the root agent directory on OSX:

`hdiutil makehybrid -o cd-rom.iso windows_base_dir/ -iso -joliet`

Add a README for how to regenerate the vsphere cdrom iso
Add a README for how to regenerate the vsphere cdrom iso

Signed-off-by: Ben Moss <80bec717c12290923c80384e0a5fc28cdf75a97e@pivotal.io>
