Resize VM disk size to something more appropriate

[pvandervelde]

The Windows 2012 R2 server image comes with a 127 Gb C-drive. That's probably a bit much for what we want it for. Would be nice if we could shrink that disk down to something more sensible (e.g 40Gb or something).

[pvandervelde]

Some suggestions for reducing the amount of data on the disk are here: http://www.hurryupandwait.io/blog/in-search-of-a-light-weight-windows-vagrant-box