This commit adds cluster map api object, cluster map
interface and it's implementation built on top of cluster map api
object.
Important note:
ClusterMap interface needs a method to identify namespace of the
cluster, it can't be a part of api object, because real source for
cluster namespace is cluster object from cluster-api upstream lib.
This will need further design discussion on how we will find
cluster-api kind: Cluster object in our manifests. For now, there
is dummy "default" namespace being used
Change-Id: I8175f54abbe77331f0c87c0bde50857ee5c0eb1d
0a7661ab7c