Add support to VMWare

[rafabene]

Actually CDK only provides support to Virtualbox, Libvirt and HyperV. We need to provide support to VMWare for those users who already have VMWare installed; until we have a native virt solution like minukube/minishift.

[hferentschik]

To begin with we would need a VMWare image which afaik we don't have. To generate one is really a issue of https://github.com/projectatomic/adb-atomic-developer-bundle. TBH, I am not sure whether it makes sense to add yet more image formats. I think it might be better to investigate and invest in a generic ISO format.

Also the Vagrant support for VMWare is commercial. Not sure how to go about testing this w/o buying licenses.