joss does not support Keystone V3 project or domain scoping during authorization

[tfelix]

The KeystoneV3Authentication does only generate a JSON payload for authorization which equals to the default scope in Keystone specs. But you should also be able to scope towards a project or domain via project/tennant name/id and or domain name/id.

Our Keystone implementations needs this scoping information in order to sucessfully authenticate a user. Otherwise a 400er error is returned.

For the specific payloads see: https://docs.openstack.org/keystone/pike/api_curl_examples.html

Judging from the description the ticket #151 might also be related to this problem.

I currently prepare a PR to provide the correct payload.