Update metadata for Grizzly

Move references form keystone to opentack-identity. Also bump the
version to 2013.1.0.
Add stub for memcached search

As the openstack-identity::server recipe seeks to enumerate memcached
servers via search, stub out a fake memcached server search result.
Upgrade chef gem to 11.2.0

As we have agreed to baseline support for these repositories on Chef11
update the Gemfile and Gemfile.lock to reflect that.
Change all spec references to openstack-identity

As this repository has been renamed, move all references from keystone
to openstack-identity.