Added boxes of Fedora 17 to the list

* Fedora 17 i386 (Puppet, Chef, VirtualBox 4.2.6);
* Fedora 17 x86_64 (Puppet, Chef, VirtualBox 4.2.6).

These boxes are created with ``veewee``.
Merge pull request #97 from henriquemoody/fedora17

Added boxes of Fedora 17 to the list