add swift resource test script
add swift resource test script

This is a little lame, but it's basically what javelin 1 & 2 and the
devstack exercises have done in the past. It's enough for now on
sanity checking, and can be enhanced if anyone wants to in the future.

Change-Id: I8a1a07e69a40e8a5ff9efa767286848a00eeabd1

openstack-dev/grenade,dtroyer/grenade,openstack-dev/grenade,dtroyer/grenade