mplement ceph.created_pool

ceph.created_pool allows the user (via yaml lines) to add pools
that the ceph_manager knows about.

Fixes: 9091
Signed-off-by: Warren Usui <warren.usui@inktank.com>
Merge pull request #106 from ceph/wip-9091-wusui

mplement ceph.created_pool

Reviewed-by: Sage Weil <sage@redhat.com>