Add kilo tag to keystone compose file

Previously, the keystone compose yml was referencing juno instead
of kilo when all other services are using kilo. This patch upates
the yml to use the keystone image with the kilo tag.

Change-Id: Ib4f551ad303bd44f0a5c45fc9d5f7d53f376caf7

compose/keystone.yml

 keystone:
-  image: kollaglue/centos-rdo-keystone:juno
+  image: kollaglue/centos-rdo-keystone:kilo
   name: keystone
   restart: always
   net: "host"