Add rules to be a required field for mapping schema

Previously the mapping schema would have validated a mapping
reference that had no rules key. This patch enforces that a rules
key be present.
I also removed the `name` key from a fixture, note that the name
key would not have made the schema fail.

bp mapping-distributed-admin

Change-Id: I64cb8a3333fe9a9372262b490348d52d1373dbb0
Merge "Add rules to be a required field for mapping schema"