fix error in unit test for log class

cdplib/unit_tests/TestLog.py

@@ -13,7 +13,7 @@ class TestLog(unittest.TestCase):
 
     def test_A_Log_Colors(self):
         self._log.info('Test Starts Here')
-        self._log.info(self._log.header + "Header")
+        self._log.info(self._log.magenta + "Header")
         self._log.info(self._log.blue + "Blue")
         self._log.info( self._log.green + "Green")
         self._log.info(self._log.yellow + "yellow")