Add final keyword to classes

src/MDConsole.php

@@ -9,7 +9,7 @@
 /**
  * Interface for CLI outputs of museum-digital's dev and admin tools.
  */
-class MDConsole {
+final class MDConsole {
 
     const STATUS_NOTICE = 0;
     const STATUS_UPDATE = 1;

src/MDOutputHandler.php

@@ -9,7 +9,7 @@
 /**
  * Class for handling outputs and logs for museum-digital's background tools.
  */
-class MDOutputHandler {
+final class MDOutputHandler {
 
     /*
      * Variables