This currently deploys the core services for a working Swift which are
account/container/object/proxy.

I've included some basic docs in docs/swift-related.rst, which gives
usage instructions and more context on this patch. These are really to
give an overview of the state of Swift in Kolla as of now, so unless
there's some major inaccuracy there please don't nitpick it.

Change-Id: Id0c54be3e24c46459c40b16b7020f05bddbe1b19
Implements: blueprint ansible-swift