Split GlusterFS install from the Elastic class

This change separates the installation of GlusterFS for Elasticsearch
snapshots from the Elasticsearch system class for better flexibility.
It also removes the use of GlusterFS for the mk20 and mk22 StackLight
labs because it generates random errors during the deployment.

https://github.com/Mirantis/mk-lab-salt-model/pull/195
2 files changed