CONTRIB: Change location of `-y` argument to apt-get
CONTRIB: Change location of `-y` argument to apt-get

in Vagrantfile. This conforms with the man page description of
apt-get; however, the form before this change should also work.

necozay/tulip-control,necozay/tulip-control,necozay/tulip-control,necozay/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,necozay/tulip-control