Added ruby 1.9.1 packages

Install ruby 1.9.1 packages to jenkins slaves.  Necessary for running
OpenStack ChefSpec cookbook tests.

Fixes: bug #1178516
Change-Id: Ibb31ea3e24bf837a7b05a8540854410dbc921b72
Reviewed-on: https://review.openstack.org/28820
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins