Partial implement fake deploy engine

This engine is very usefull when we have already deployed OpenStack
cloud and would like to test it with Rally.

On deploy it just returns cloud config (endpoints users and so on)
that was specified in task config.

TODO: Add verification for input endpoints

blueprint deploy-engine-fake

Change-Id: I5c139f6b97312b6e4e00913c0a987f0bfbcb203f