Marshal dict and not a slice

@@ -46,11 +46,7 @@ func (v Version) Register() {
 }
 
 func (vMap versionMap) Json() ([]byte, error) {
-	vSlice := make([]Version, len(vMap))
-	for _, v := range vMap {
-		vSlice = append(vSlice, v)
-	}
-	return json.Marshal(vSlice)
+	return json.Marshal(vMap)
 }
 
 // vim: ts=4 sts=4 sw=4 noet tw=72: