Allow non-admin user to validate his own data

This blueprint is a part of openstack-identity-service.

Currently, non-admin user can retrieve a token (by providing his login and password), but he cannot get a list of his roles and tenants (only an admin is allowed to do such things).

A non-admin user should be allowed to validate his own data (i.e. get a list of his roles etc.)

Required changes.
1. IdentitySevice.validate_token should be patched (https://github.com/aababilov/keystone/commit/91b08489f16bc700a248aefba68f94faf9b7132a).
2. admin_token field should be removed from auth_token.AuthProtocol class and from /etc/nova/{api-paste.ini,auth_token.ini} files