no more duplication of test suites.

Parsing the test tree and deciding in the marsheller whether it is a
testcase (leaf) or a suite (non-leaf)

cmd/go2junit/go2junit.go

@@ -9,8 +9,43 @@ import (
 	"path/filepath"
 )
 
-func main() {
+func (t *Test) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
+	if len(t.Tests) == 0 {
+		start.Name = xml.Name{Local: "testcase"}
+		classname := ""
+		if t.Parent != nil {
+			classname = t.Parent.Name
+		}
+		var skipped *Result
+		if t.Skipped > 0 {
+			skipped = &Result{
+				Message: "skipped",
+			}
+		}
+		var failed *Result
+		if t.Failures > 0 {
+			failed = &Result{
+				Message: "failed",
+			}
+		}
+		tc := Testcase{
+			Name: t.Name,
+			// parent class name
+			Classname: classname,
+			Time:      t.Time,
+			Skipped:   skipped,
+			Error:     nil,
+			Failure:   failed,
+			SystemOut: t.SystemOut,
+		}
+		return e.EncodeElement(tc, start)
+	}
+	type Alias Test
+	start.Name = xml.Name{Local: "testsuite"}
+	return e.EncodeElement(Alias(*t), start)
+}
 
+func main() {
 	/*
 		testsuites := Testsuites{
 			Time:      1.23,