Using mariadb in OpenSuSE >= 13.1.

I would like to use MariaDB instead of MySQL on OpenSuSE 13.1. Looking at what has been done for other operatingsystem versions in the source (manifests/params.pp), it appears that you have settled on using operatingsystemrelease to determine when to select mariadb packages, so I have done the same for OpenSuSE.  Hopefully I have done this is a way that works for your process; I'm kind of new to contributing to other folks' projects.

Ticket: https://tickets.puppetlabs.com/browse/MODULES-1337
Does the version need to be so specific? Could we do

```puppet
if $::operatingsystemmajrelease >= 13 {
```
?