Fix the path of memcached config file

On CentOS, the correct location of memcached is
/etc/sysconfig/memcached (without .conf).

Closes-bug: #1265403
Closes-bug: #1286907
Change-Id: Idaac8920c1954d917fe533031fb0ff2416d5b339
(cherry picked from commit a9737d0fe1d178659f1175136eb2a46ba64645c1)
Add auth_uri option

'Configuring auth_uri to point to the public identity endpoint is
required; clients may not be able to authenticate against an admin
endpoint.' If auth_uri is not set, such warning will be logged.

Change-Id: Ic7d317e04de921636e0c3fb900b4195c48f73671
Closes-Bug: #1279730
ref: https://github.com/openstack/python-keystoneclient/blob/master/keystoneclient/middleware/auth_token.py
(cherry picked from commit c8e7067502e57811a8e98434a4d5a41b0e9ca790)
Merge "Add auth_uri option" into stable/havana