Added support for optionally creating the elasticsearch user and group before installing elasticsearch.

Renamed vars, set the tasks to use the es_user and es_group vars in elasticsearch-optional-user.yml. Modifed README.md to list the es_user_id and es_group_id vars, made note that both vars are required if they are used. Removed the commented out instances of the vars in defaults/main.yml.

Added es_user, es_group, es_user_id, es_group_id vars to config testing.

Made conditionals use explicit 'is defined' test.

Add tests for es_user_id and es_group_id.

Update defaults/main.yml and test/integration/config.yml to match master plus test config additions.

test/integration/helpers/serverspec/config_spec.rb

@@ -5,6 +5,14 @@ shared_examples 'config::init' do |es_version|
   describe user('elasticsearch') do
     it { should exist }
   end
+  
+  describe group('elasticsearch') do
+    it { should have_gid 333 }
+  end
+
+  describe user('elasticsearch') do
+    it { should have_uid 333 }
+  end
 
   describe service('node1_elasticsearch') do
     it { should be_running }