mw/kubernetes: remove kPod and kServices (#969)

Based up on: #939, but redone in a new PR with some cherry-picked
commits:
aacb91ef0b
5dc34247b7

This removes kPod and Kservice and creates []msg.Service from k.findPods
and k.findServices.

Updated few tests which I *think* are correct; they look correct to me.

middleware/kubernetes/federation.go

@@ -29,7 +29,7 @@ func (k *Kubernetes) Federations(state request.Request, fname, fzone string) (ms
 	if err != nil {
 		return msg.Service{}, err
 	}
-	r, err := k.parseRequest(state)
+	r, err := parseRequest(state)
 
 	lz := node.Labels[LabelZone]
 	lr := node.Labels[LabelRegion]