Vagrantfile for setting up an environment

git clone and vagrant up are now enough to set up a testing 
environment in a vm. no more need for contributors to hassle with 
dependencies and installing things that are required to run this program.

On Windows hosts npm sometimes has issues with installing from the 
shared /vagrant folder due to max path length and symlinks. The 
--no-bin-links flag didn't solve this, an alternative might be to symlink
/vagrant/node_modules to somewhere else on the vm but that's a bit
hacky, instead the install_shared_folder.sh script copies the shared 
/vagrant directory to the vm every time it is run, this resolves the issue.