Unsupported OS -  RedHat

Unsupported OS -  RedHat... when just running the most basic setup.

```
class {'l23network': 
  use_ovs=>true
}
```

error on line 48 of params.pp

facter shows this:

```
operatingsystem => RedHat
operatingsystemmajrelease => 6
operatingsystemrelease => 6.7
osfamily => RedHat
```

Any advice appreciated,
Chris.
