Add some server settings

 - elasticsearch_transport_tcp_port
 - elasticsearch_discovery_zen_ping_multicast_enabled
 - elasticsearch_discovery_zen_ping_unicast_hosts
More useless copypaste
Add rest_enable_cors setting
Merge pull request #1 from Jimdo/add_some_settings

Add some settings
adds puppetlabs_spec_helper to test the module
adds the option to specify a max heap size for the server