To working properly with GlusterFS backend cinder-volume needs
some original libs and utilities from GlusterFS distribution. For
RedHat-based OSes that libs provided by glusterfs-fuse package, so
I add it to requirements instead of glusterfs. We shouldn't add
glusterfs package explicitly and can use only glusterfs-fuse as
requirement, cause glusterfs-fuse depends on glusterfs package.
Change-Id: I674b6f4cbbc9f33cb9c3cd49852fddcb1e003791
Closes-Bug: #1397010