add HCFS cluster unit test

Signed-off-by: rootfs <hchen@redhat.com>
add document of how to use CephFS as an example of HCFS

Signed-off-by: rootfs <hchen@redhat.com>
use core-site.xml

Signed-off-by: rootfs <hchen@redhat.com>
relocate core-site.xml

Signed-off-by: rootfs <hchen@redhat.com>
relocate core-site.xml

Signed-off-by: rootfs <hchen@redhat.com>