Making token validation api returns service catalog

Currently access info token validation api returned doesn't include
service catalog dict, it causes some projects couldn't work well as it
designed: upperlayer project uses those endpoints to call other servies
for the necessary handling of function, e.g. Heat, as an example the
follow execution stack could be triggered by a standard stack creation
usecase. And, as code logic shown, keystoneclient has such related
parsing and construction logic as well.

https://github.com/openstack/heat/blob/master/heat/engine/properties.py#L296
  https://github.com/openstack/heat/blob/master/heat/engine/constraints.py#L576
    https://github.com/openstack/heat/blob/master/heat/engine/clients/os/glance.py#L35
      https://github.com/openstack/heat/blob/master/heat/engine/clients/client_plugin.py#L50
        https://github.com/openstack/heat/blob/master/heat/common/heat_keystoneclient.py#L196
          https://github.com/openstack/python-keystoneclient/blob/master/keystoneclient/httpclient.py#L174
            https://github.com/openstack/python-keystoneclient/blob/master/keystoneclient/access.py#L532
              https://github.com/openstack/python-keystoneclient/blob/master/keystoneclient/service_catalog.py#L271

Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge pull request #149 from LiuZhiyan/return-service-catalog-token-validation-api

Making token validation api returns service catalog