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/owner_new_test.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestOwnerNewBasics(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	if _, err := ownerNew("test@example.com", "Test", "hunter2"); err != nil {
+		t.Errorf("unexpected error when creating new owner: %v", err)
+		return
+	}
+}
+
+func TestOwnerNewClash(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	if _, err := ownerNew("test@example.com", "Test", "hunter2"); err != nil {
+		t.Errorf("unexpected error when creating new owner: %v", err)
+		return
+	}
+
+	if _, err := ownerNew("test@example.com", "Test", "hunter2"); err == nil {
+		t.Errorf("expected error not found when creating with clashing email")
+		return
+	}
+}
+
+func TestOwnerNewEmpty(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	if _, err := ownerNew("test@example.com", "", "hunter2"); err == nil {
+		t.Errorf("expected error not found when passing empty name")
+		return
+	}
+
+	if _, err := ownerNew("", "", ""); err == nil {
+		t.Errorf("expected error not found when passing empty everything")
+		return
+	}
+}