Add initial glusterfs module
Add start method to glusterfs module
Add gluster cluster state
Add peered status
Make peers plural for glusterfs
Fix lint errors for gluster modules
Clean up glusterfs module and state

Cleaning up a few small things.
Merge pull request #10486 from gtmanfred/glusterfs

Add glusterfs state and module
Merge pull request #10488 from s0undt3ch/develop

Unify the minimal libcloud version requirement.
Remove unused import. Don't shaddow `peer()`.
Remove un-used import.