Vagrantfile fixes for vagrant 2.0

[artw]

• Fix the array, it does not work at all otherwise.

• Add persistent device naming whitelist flag (vagrant warning)

• Add a crutch for changes in /etc/photon-release that conflict with vagrant plugin detection

• New vars folder with jsons for ease of building images

[frapposelli]

@artw looking good! can you please amend the README as well?

[frapposelli]

awesome, thanks!

[artw]

could you (ask someone to) build and push a new image to https://app.vagrantup.com/vmware/boxes/photon ?

[frapposelli]

will do

[artw]

thanks!

[frapposelli]

@artw it is done! https://app.vagrantup.com/vmware/boxes/photon/versions/2.0.0

[artw]

perfect, thank you!