[Hubs-devel] Vagrantfile.example was updated

[Ryan Lerch]

In a recent commit [1], the Vagrantfile.example was updated to use Fedora
27 rather than Fedora 25. So if you are using Vagrant to hack on hubs,
things might get a little funky.

When first setting up the Vagrant dev instance, you need to copy
`Vagrantfile.example` to `Vagrantfile`, (`Vagrantfile` is not stored in the
repo). So be sure to either update your Vagrantfile, or if you havent
changed it, just re-copy it over from Vagrantfile.example after git pulling.

cheers,
ryanlerch

[1] -
https://pagure.io/fork/abompard/fedora-hubs/c/4be8ee52d3696d7a09d774d2d71...