Simplify PSR-4 autoload

classes/Exception/InvalidTimeException.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Alltube\Library\Exception;
+
+/**
+ * Invalid time.
+ */
+class InvalidTimeException extends AlltubeLibraryException
+{
+
+    /**
+     * InvalidTimeException constructor.
+     * @param string $time Invalid time
+     */
+    public function __construct($time)
+    {
+        parent::__construct('Invalid time: ' . $time);
+    }
+}