- Stop checking for to_dict, breaking compatibility with older sdk
  releases
- Updates RETURN doc string with all the returned fields
- Adds a new identity_role_info role to test the identity_role_info
  module.
- Change the name of the module return value to remove 'openstack_'
  prefix

Change-Id: If8a1145a31d685d41367383930e6fd08d64c6ae8