Set Codelyber#GREETING constant as private in order to encapsulate it avoiding calling it form test cases

Author: JavierCane

src/Codelyber.php

@@ -7,7 +7,7 @@
 final class Codelyber
 {
     /** string */
-    const GREETING = "CodelyTV";
+    private const GREETING = "CodelyTV";
 
     /** @var string */
     private $name;