test: remove health reload test (#1142)

Flaky test because it used a fix port; just drop it. Might be worthwhile
to return it as a unit tests, but on that level we can't use a coredns
"process" to exercise the reload.

test/health_reload_test.go

-package test
-
-import (
-	"io/ioutil"
-	"log"
-	"net/http"
-	"testing"
-)
-
-func TestHealthReload(t *testing.T) {
-	log.SetOutput(ioutil.Discard)
-
-	// Corefile with for example without proxy section.
-	corefile := `example.org:0 {
-	health localhost:35080
-}
-`
-	i, err := CoreDNSServer(corefile)
-	if err != nil {
-		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
-	}
-
-	resp, err := http.Get("http://localhost:35080/health")
-	if err != nil {
-		t.Fatalf("Could not get health: %s", err)
-	}
-	body, err := ioutil.ReadAll(resp.Body)
-	if x := string(body); x != "OK" {
-		t.Fatalf("Expect OK, got %s", x)
-	}
-	resp.Body.Close()
-
-	i, err = i.Restart(NewInput(corefile))
-	if err != nil {
-		t.Fatalf("Could not restart CoreDNS serving instance: %s", err)
-	}
-
-	defer i.Stop()
-
-	resp, err = http.Get("http://localhost:35080/health")
-	if err != nil {
-		t.Fatalf("Could not get health: %s", err)
-	}
-	body, err = ioutil.ReadAll(resp.Body)
-	if err != nil {
-		t.Fatalf("Could not get resp.Body: %s", err)
-	}
-	if x := string(body); x != "OK" {
-		t.Fatalf("Expect OK, got %s", x)
-	}
-	resp.Body.Close()
-}