Remove the word middleware (#1067)

* Rename middleware to plugin

first pass; mostly used 'sed', few spots where I manually changed
text.

This still builds a coredns binary.

* fmt error

* Rename AddMiddleware to AddPlugin

* Readd AddMiddleware to remain backwards compat

plugin/kubernetes/ns_test.go

@@ -0,0 +1,69 @@
+package kubernetes
+
+import (
+	"testing"
+
+	"k8s.io/client-go/1.5/pkg/api"
+)
+
+type APIConnTest struct{}
+
+func (APIConnTest) Run()                          { return }
+func (APIConnTest) Stop() error                   { return nil }
+func (APIConnTest) PodIndex(string) []interface{} { return nil }
+
+func (APIConnTest) ServiceList() []*api.Service {
+	svc := api.Service{
+		ObjectMeta: api.ObjectMeta{
+			Name:      "dns-service",
+			Namespace: "kube-system",
+		},
+		Spec: api.ServiceSpec{
+			ClusterIP: "10.0.0.111",
+		},
+	}
+
+	return []*api.Service{&svc}
+
+}
+
+func (APIConnTest) EndpointsList() api.EndpointsList {
+	return api.EndpointsList{
+		Items: []api.Endpoints{
+			{
+				Subsets: []api.EndpointSubset{
+					{
+						Addresses: []api.EndpointAddress{
+							{
+								IP: "127.0.0.1",
+							},
+						},
+					},
+				},
+				ObjectMeta: api.ObjectMeta{
+					Name:      "dns-service",
+					Namespace: "kube-system",
+				},
+			},
+		},
+	}
+}
+
+func (APIConnTest) GetNodeByName(name string) (api.Node, error) { return api.Node{}, nil }
+
+func TestNsAddr(t *testing.T) {
+
+	k := New([]string{"inter.webs.test."})
+	k.APIConn = &APIConnTest{}
+
+	cdr := k.nsAddr()
+	expected := "10.0.0.111"
+
+	if cdr.A.String() != expected {
+		t.Errorf("Expected A to be %q, got %q", expected, cdr.A.String())
+	}
+	expected = "dns-service.kube-system.svc."
+	if cdr.Hdr.Name != expected {
+		t.Errorf("Expected Hdr.Name to be %q, got %q", expected, cdr.Hdr.Name)
+	}
+}