Copy proxy unit test from OpenStack Swift

This is a copy of the proxy unit test from OpenStack
Swift.  The file has minor changes to make it compatible
with Gluster For Swift.

Change-Id: I64a0f8d274461eb2a2c38524c6282e0d3d3d1457
Signed-off-by: Luis Pabon <lpabon@redhat.com>
Reviewed-on: http://review.gluster.org/5113
Reviewed-by: Peter Portante <pportant@redhat.com>
Tested-by: Peter Portante <pportant@redhat.com>