Instructions for installing on fedora 20

A start on the documentation parts of: https://clusterhq.atlassian.net/browse/FLOC-970
I tried these instructions on the chef/fedora-20 virtualbox vagrant image.  The result was:

```
kernel-devel-3.11.10-301.fc20.x86_64.rpm                                                                                                                                                      | 8.4 MB  00:01:38     
Examining /var/tmp/yum-root-iTniTD/kernel-devel-3.11.10-301.fc20.x86_64.rpm: kernel-devel-3.11.10-301.fc20.x86_64
/var/tmp/yum-root-iTniTD/kernel-devel-3.11.10-301.fc20.x86_64.rpm: does not update installed package.
Error: Nothing to do
```

Sounds like it didn't work?