Update AdderTest.php

Author: mpkelly

Diff for: tests/AdderTest.php

@@ -9,6 +9,6 @@ public function test_add()
 	{
 		$result = \Adder\add(1, 2 );
 
-		$this->assertSame(2, $result);
+		$this->assertSame(3, $result);
 	}
 }