api: Add go files

I know this is a huge commit, but I can't be bothered to check
this in part by part.

api/domain_moderator_new_test.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestDomainModeratorNewBasics(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	if err := domainModeratorNew("example.com", "test@example.com"); err != nil {
+		t.Errorf("unexpected error creating new domain moderator: %v", err)
+		return
+	}
+}
+
+func TestDomainModeratorNewEmpty(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	if err := domainModeratorNew("example.com", ""); err == nil {
+		t.Errorf("expected error not found when creating new moderator with empty email")
+		return
+	}
+
+	if err := domainModeratorNew("", "test@example.com"); err == nil {
+		t.Errorf("expected error not found when creating new moderator with empty domain")
+		return
+	}
+}