Adds name to centos repo

Without the descr, yum will throw a harmless error every time you try and install software

    Repository 'logstash' is missing name in configuration, using id

Note: It seems counter intuitive, but puppet yumrepo uses 'descr' to set the 'name', where as 'name' does nothing. 
https://groups.google.com/forum/#!topic/puppet-users/QEM0XquEyLY

Also, I swear I submitted this pull request an hour ago, but I can't find it, so I'm submitting it again.