Add some authtoken related attributes

This change adds some attributes into the cookbook so
that they are configurable. It mainly includes:
cafile, memcached_servers, memcache_security_strategy,
memcache_secret_key, insecure and hash_algorithms.

Change-Id: Ic48bd7193815185f1c065c1bd689d67de325cd8e
Closes-Bug: #1371421