Vagrant file that installs specified software

https://github.com/jamesandrewsmith/devtools/issues/16

* Specified software is configured as an array in the Vagrantfile
* Will run "software_name/configure.ps1" if it exists
* Pulls down devtools into .vagrant directory
Vagrantfile needs to be extensionless

https://github.com/jamesandrewsmith/devtools/issues/16