Add Windows

[mcandre]

TODO:

• Fix config.vm.provision "shell", path: "bootstrap.ps1" in test Vagrantfile
• Promote config.vm.communicator = "winrm" to a Vagrantfile template for packer
• Have OpenSSH installed and configured during packer, in preparation for vagrant ssh.
• Finish testing bidirectional sync.
• Ensure vagrant ssh -c '...' works
• Promote config.vm.synced_folder ".", "/cygdrive/c/vagrant", type: "rsync" to Vagrantfile template for packer.

Theories for fixing various Windows guest issues:

• Add bash.exe to PATH to workaround hardcoded bash -l limitation for vagrant ssh -c ...
• Explicitly configure the base box as a Windows guest.

Theories for installing bash.exe:

• Install git and ensure that bash.exe is in PATH.
• Install and setup bash on Ubuntu on Windows AKA Windows Linux Subsystem.

Examples:

https://github.com/lwieske/packer-windows2016-core/blob/master/windows2016-core.json

https://github.com/rgl/windows-2016-vagrant/blob/master/windows-core-insider-2016.json

https://github.com/mwrock/packer-templates/blob/master/vbox-2016.json

https://github.com/joefitzgerald/packer-windows/blob/master/windows_10.json

https://github.com/boxcutter/windows

https://github.com/gildas/packer-windows/blob/master/templates/cic/packer.json