New Fedora 27 box

[Tirloni, Giovanni]

Fedora 27 was released yesterday (https://fedoramagazine.org/announcing-fedora-27) and we have a new Vagrant box for it.

   https://app.vagrantup.com/inclusivedesign/boxes/fedora27

It comes with GNOME 3.26, Firefox 57, Chrome 62 and Docker pre-configured.

To use the new box in an existing project:
1. Edit your Vagrantfile (Update this line:  config.vm.box = "inclusivedesign/fedora27")
2. vagrant destroy -f
3. vagrant up

To remove old boxes:
1. vagrant box remove inclusivedesign/fedora26
2. vagrant box prune