Added TestDate class to help format dates correctly

lib/Test.js

@@ -1,5 +1,20 @@
 'use strict';
 
+/**
+ * A class that represents the date of a test
+ */
+class TestDate extends Date {
+	/**
+	 * Overwrite the default string casting implementation to format
+	 * all dates in the British format
+	 *
+	 * @returns {string} The formatted date
+	 */
+	toString() {
+		return this.toLocaleDateString('en-GB');
+	}
+}
+
 class Test {
 	testId;
 	testTemplateId;