Enable mariadb service.

On Fedora 20, the mysqld service is called mariadb.  While there is a
symlink from mysqld->mariadb, there is an issue with that approach and
systemd. So, we need to explicitally enable mariadb if the mysqld
enablement fails.

Change-Id: Ideee870aba5275987233c8411d57024ac7def695
See: https://bugzilla.redhat.com/show_bug.cgi?id=1014311