Vagrant: update APT index before installing packages

The bootstrap script fails when the APT index in the base box
is not up to date, as it will try to install obsolete packages
and get 404 errors.

deployment/vagrant-common/bootstrap.sh

@@ -90,6 +90,7 @@ if [ ! -e "~/.firstboot" ]; then
 
   # Install prerequisite tools
   echo "Installing prerequisites"
+  sudo apt-get update
   sudo apt-get install -y git
   sudo apt-get install -y python-pip