Update to juno

1 . pipeline change: https://github.com/openstack/ceilometer/commit/fec77dbc85fed701fdbc3a96bae57e5ae3a705cb

2. ceilometer.conf changes based on http://docs.openstack.org/juno/config-reference/content/ceilometer-conf-changes-juno.html

3. Other keys that are now missing, but not mentioned in the link above: 
 ``auth_host auth_port auth_protocol`` - I expect ``auth_uri`` is enough
 ``admin_user admin_password admin_tenant_name``