Add a slave-script to Jenkins for pushing to swift

I042cdd2dd2407f381cafcabc5c6b83d9b9a9eb00 adds instructions to
workers on how to send logs to swift using the FormPost middleware.
This slave-script allows you to pass in a directory to push to
swift using these instructions and returns a URL where they are
available.

Change-Id: I7ccafa408a88ef80317b1c546b3451c0033dce61
Merge "Add a slave-script to Jenkins for pushing to swift"