def installed_vagrant_box_names(node)
      (`cd #{node.project_root} && vagrant box list`).split("\n").map{|vagrant_box| vagrant_box.split(' ').first}
    end
def installed_vagrant_box_names(node)
      (`cd #{node.project_root} && vagrant box list`).split("\n").map{|vagrant_box| vagrant_box.split(' ').first}
    end
return an Array with the names of the currently installed vagrant boxes
 @returns Array