mw/kubernetes: remove federation and cidr (#916)

* mw/kubernetes: remove federation and cidr

Remove both as we have a corefile syntax change that handles cidr and
remove federation because that is going to be its own middleware.

* backwards incompat changes

This PR:
* removes cidr from kubernetes (core Corefile feature now)
* removes federation from kubernets (comes back as new middleware)
* [remove autopath - which was already gone, so that already was
  backwards incompat]
* adds `fallthrough` to the *etcd* middleware and makes you enable it.
* Fail on unknown properties
* documentation
* Disable TestHealthCheck as it uses realtime and fails

middleware/kubernetes/reverse_test.go

@@ -1,33 +0,0 @@
-package kubernetes
-
-import (
-	"net"
-	"testing"
-)
-
-func TestIsRequestInReverseRange(t *testing.T) {
-
-	tests := []struct {
-		cidr     string
-		name     string
-		expected bool
-	}{
-		{"1.2.3.0/24", "4.3.2.1.in-addr.arpa.", true},
-		{"1.2.3.0/24", "5.3.2.1.in-addr.arpa.", true},
-		{"5.6.0.0/16", "5.4.6.5.in-addr.arpa.", true},
-		{"1.2.3.0/24", "5.4.2.1.in-addr.arpa.", false},
-		{"5.6.0.0/16", "5.4.2.1.in-addr.arpa.", false},
-		{"5.6.0.0/16", "5.6.0.1.in-addr.arpa.", false},
-	}
-
-	k := Kubernetes{}
-
-	for _, test := range tests {
-		_, cidr, _ := net.ParseCIDR(test.cidr)
-		k.ReverseCidrs = []net.IPNet{*cidr}
-		result := k.isRequestInReverseRange(test.name)
-		if result != test.expected {
-			t.Errorf("Expected '%v' for '%v' in %v.", test.expected, test.name, test.cidr)
-		}
-	}
-}