WIP: Add RHEL and Centos support to vagrant-flapjack

@jessereynolds 
Why do we do this?  Do we need this to make icinga start up correctly?

On centos 6, the process table shows:

```
icinga   10535  0.0  0.0 140296  1972 ?        Ssl  08:25   0:00 /usr/bin/icinga -d /etc/icinga/icinga.cfg
```