adds a second yaml configuration file for cassandra 2.0.x

[dcosson]

Solves issue https://github.com/gini/puppet-cassandra/issues/13

[stagrlee]

Love this patch. With the latest Oracle JDK, this gets me up and running

class { 'cassandra':
  cluster_name        => 'ditCluster',
  seeds               => [ '10.0.0.17', '10.0.0.18', '10.0.0.21', ],
  package_name        => 'dsc20',
  thread_stack_size   => '256',
}

[tbarbugli]

+1