GetNameservers is inconsistent across providers (#655)

* Warn if GetNameservers returns FQDN+dot strings
* Simplify logic that covers for the inconsistency
* Fix azuredns, gcloud, bind, route53
* Clean up cloudflare, digitalocean, dnsimple, gandi_v5, namedotcom

models/tonameservers_test.go

@@ -0,0 +1,51 @@
+package models
+
+import (
+	"testing"
+)
+
+func TestToNameservers(t *testing.T) {
+	nss, e := ToNameservers([]string{"example.com", "example2.tld"})
+	if e != nil {
+		t.Errorf("error e %v (%v)", e, nss)
+	}
+	if len(nss) != 2 {
+		t.Errorf("error len: %v", nss)
+	}
+	if nss[0].Name != "example.com" {
+		t.Errorf("error 0: %v", nss[0].Name)
+	}
+	if nss[1].Name != "example2.tld" {
+		t.Errorf("error 1: %v", nss[1].Name)
+	}
+}
+
+func TestToNameservers_neg(t *testing.T) {
+	nss, e := ToNameservers([]string{"example.com.", "example2.tld."})
+	if e == nil {
+		t.Errorf("error 3 (%v)", nss)
+	}
+}
+
+func TestToNameserversStripTD(t *testing.T) {
+	nss, e := ToNameserversStripTD([]string{"example.com.", "example2.tld."})
+	if e != nil {
+		t.Errorf("error e %v (%v)", e, nss)
+	}
+	if len(nss) != 2 {
+		t.Errorf("error len: %v", nss)
+	}
+	if nss[0].Name != "example.com" {
+		t.Errorf("error 0: %v", nss[0].Name)
+	}
+	if nss[1].Name != "example2.tld" {
+		t.Errorf("error 1: %v", nss[1].Name)
+	}
+}
+
+func TestToNameserversStripTD_neg(t *testing.T) {
+	nss, e := ToNameserversStripTD([]string{"example.com", "example2.tld"})
+	if e == nil {
+		t.Errorf("error e (%v)", nss)
+	}
+}