This change is required to return 'request_id' from client
to log request_id mappings of cross-project requests.

Instantiating class 'keystoneclient.v3.client.Client' using
'include_metadata=True' will cause manager response to return
a new 'Response' class instead of just the data. This 'Response'
class is going to have additional metadata properties available
like 'request_ids' and the original data will be available as
property 'data' to it.

This change is backward compatible since user has to set a new
parameter 'include_metadata=True' to client in order to get the
request_id returned.

Co-author: Dinesh Bhor <dinesh.bhor@nttdata.com>
Partially Implements: blueprint return-request-id-to-caller
Change-Id: Ibefaa484158ff08bfcacc1e2802d87fc26fd76a5

Change-Id: I50a3011c302fb5568da8f57e2f5c354d1afb3a94

Change-Id: I881fca9b06f551fd26b37fdb43502a71da8ffec8

Change-Id: I748fadaececc4c5fe67ab6d671f13ce4ea964049
I44f2950a092bc03bdd0a9976242689a8f198b07a
I5f4dccaef48902bb4a5e6eab304c76cc5dbb258d

For compliance with the Project Testing Interface as described in:

https://governance.openstack.org/tc/reference/project-testing-interface.html

Refer to:

http://lists.openstack.org/pipermail/openstack-dev/2017-November/124815.html

Change-Id: Iaa1530f19049883fc9fbce66f1fcc82ded559a07

Change-Id: Ie0a8594f2dd0554a07111207899e6134affc998e