Add param use_no_cache to the openstack::auth_file

Fix bug 1169993

   This patch contains:
      *  use_no_cache param will add BooleanVar OS_NO_CACHE to the openrc,
         in the default its value is true.
      *  add the openstack_auth_file_spec for test.

Change-Id: I3885bccb4c06bbe652f7fee1d5db83913d8cd79b