gluster-swift-gen-builders behaviour changes

gluster-swift-gen-builders now changes directory to /etc/swift prior to
creating ring files. It does display a message indicating the location of
the ring files.

BUG: 986458

https://bugzilla.redhat.com/show_bug.cgi?id=986458

Change-Id: Iea33c925d98c47c914e8a95d11faa3220967b4d6
Signed-off-by: Chetan Risbud <crisbud@redhat.com>
Reviewed-on: http://review.gluster.org/5658
Reviewed-by: Luis Pabon <lpabon@redhat.com>
Tested-by: Luis Pabon <lpabon@redhat.com>