Keystone2KeystoneAuthPlugin scoping capabilities
Keystone2KeystoneAuthPlugin scoping capabilities

This enhancement takes care of scoping remote federated token in case
scoping information were provided by a user. Otherwise it will return
unscoped token wrapped with ``access.AccessInfoV3`` object.

Change-Id: I99b00df12c04517b5ffa1fe72e6b69d52d41d8a6
Implements: bp k2k-auth-plugin

sileht/keystoneauth,jamielennox/keystoneauth,citrix-openstack-build/keystoneauth