middleware/kubernetes: doc cleanup (#571)

Set of small cleanups.

middleware/kubernetes/README.md

 # kubernetes
 
 *kubernetes* enables reading zone data from a kubernetes cluster.
-It implements the spec defined for kubernetes DNS-Based service discovery:
-   https://github.com/kubernetes/dns/blob/master/docs/specification.md
-
-Examples:
+It implements the [spec](https://github.com/kubernetes/dns/blob/master/docs/specification.md)
+defined for kubernetes DNS-Based service discovery:
 
 Service `A` records are constructed as "myservice.mynamespace.svc.coredns.local" where:
 
@@ -30,9 +28,9 @@ Endpoint `A` records are constructed as "epname.myservice.mynamespace.svc.coredn
 
 Also supported are PTR and SRV records for services/endpoints.
 
-## Configuration Syntax
+## Syntax
 
-This is an example kubernetes middle configuration block, with all options described:
+This is an example kubernetes configuration block, with all options described:
 
 ```
 # kubernetes <zone> [<zone>] ...

middleware/kubernetes/handler.go

@@ -45,7 +45,7 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
 	)
 	switch state.Type() {
 	case "A":
-		records, _, err = middleware.A(&k, zone, state, nil, middleware.Options{}) // Hmm wrt to '&k'
+		records, _, err = middleware.A(&k, zone, state, nil, middleware.Options{})
 	case "AAAA":
 		records, _, err = middleware.AAAA(&k, zone, state, nil, middleware.Options{})
 	case "TXT":

middleware/kubernetes/kubernetes.go

@@ -151,9 +151,7 @@ func (k *Kubernetes) IsNameError(err error) bool {
 }
 
 // Debug implements the ServiceBackend interface.
-func (k *Kubernetes) Debug() string {
-	return "debug"
-}
+func (k *Kubernetes) Debug() string { return "debug" }
 
 func (k *Kubernetes) getClientConfig() (*rest.Config, error) {
 	// For a custom api server or running outside a k8s cluster

middleware/kubernetes/kubernetes_test.go

@@ -84,7 +84,6 @@ func TestParseRequest(t *testing.T) {
 	}
 
 	// Test A request of endpoint
-	//
 	query = "1-2-3-4.webs.mynamespace.svc.inter.webs.test."
 	r, e = k.parseRequest(query, "A")
 	if e != nil {
@@ -104,8 +103,6 @@ func TestParseRequest(t *testing.T) {
 	}
 
 	// Invalid query tests
-	//
-
 	invalidAQueries := []string{
 		"_http._tcp.webs.mynamespace.svc.inter.webs.test.", // A requests cannot have port or protocol
 		"servname.ns1.srv.inter.nets.test.",                // A requests must have zone that matches corefile