Exception on unauthorized user/pass/token

[Leandro Ignacio Costantino]

( couldn't find mistral client launchpad )

When Mistral API fails to authenticate against keystone:
2014-05-05 16:48:52.479 30993 WARNING keystoneclient.middleware.auth_token [-] Unexpected response from keystone service: {u'error': {u'message': u'Invalid user / password', u'code': 401, u'title': u'Unauthorized'}}
2014-05-05 16:48:52.479 30993 WARNING keystoneclient.middleware.auth_token [-] Authorization failed for token
2014-05-05 16:48:52.480 30993 INFO keystoneclient.middleware.auth_token [-] Invalid user token - rejecting request
localhost - - [05/May/2014 16:48:52] "GET /v1/workbooks HTTP/1.1" 401 23

mistral-client return a ValueError exception since it's trying to decode as json the "Authorization Failed" message.

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/92198
Committed: https://git.openstack.org/cgit/stackforge/python-mistralclient/commit/?id=762e1cdc3c50b677555ef99207cfdf3f609cdc3d
Submitter: Jenkins
Branch: master

commit 762e1cdc3c50b677555ef99207cfdf3f609cdc3d
Author: Leandro I. Costantino <email address hidden>
Date: Mon May 5 16:55:33 2014 -0300

    Return response as error if not valid json object

    If the response returned by Mistral do not contain a valid json an
    exception is thrown by the client due to invalid json format.
    If there's a ValueError exception and it's an error code try to return
    the response text instead. (Ex: Authorization Failed )

    This may be a temporary fix if the BE is able to return the json
    error msg returned by keystone.

    Change-Id: I540f3aaa35fb15adc04bf0a33e46af8ac614c814
    Closes-Bug: #1316298