Install mariadb-galera-server

Set package_name to 'mariadb-galera-server' so that it is always
installed when calling mysql::server. This will not deploy a galera
cluster since, by default, clustering is disabled.
Merge pull request #213 from rohara/common-db-galera

Install mariadb-galera-server
switch from mysql-server to mariadb-galera-server
Merge pull request #232 from cwolferh/mariadb_galera_package_name

switch from mysql-server to mariadb-galera-server