[api] set `is_admin_project` on tokens for admin project
[api] set `is_admin_project` on tokens for admin project

This patch update api_doc to include 'is_admin_project'

Change-Id: I7d8345ea75659f6397098979531edf286df69485
Closes-Bug:#1523012

openstack/keystone,rajalokan/keystone,mahak/keystone,ilay09/keystone,mahak/keystone,openstack/keystone,ilay09/keystone,rajalokan/keystone,rajalokan/keystone,openstack/keystone,ilay09/keystone,mahak/keystone