Updated README

Author: dantleech

README.md

@@ -14,14 +14,22 @@ Usage
 -----
 
 ````php
+<?php
+
+use Symfony\Component\Console\Output\NullOutput;
+use DTL\PhpcrMigrations\VersionStorage;
+use DTL\PhpcrMigrations\VersionFinder;
+use DTL\PhpcrMigrations\Migrator;
+
 $storage = new VersionStorage($phpcrSession);
 $finder = new VersionFinder(array('/path/to/migrations'));
 
 $versions = $finder->getVersionCollection();
 $migrator = new Migrator($session, $versionCollection, $storage);
 
 $to = '201504241744';
-$migrator->migrate($to);
+$output = new NullOutput();
+$migrator->migrate($to, $output);
 ````
 
 Versions
@@ -32,6 +40,8 @@ Version classes contain `up` and `down` methods. The class is quite simple:
 ````php
 <?php
 
+use DTL\PhpcrMigrations\VersionInterface;
+
 class Version201504241200 implements VersionInterface
 {
     public function up(SessionInterface $session)