refactored session and added unit tests for manager and driver.

tests/Session/SessionManagerTest.php

@@ -0,0 +1,29 @@
+<?php
+
+class SessionManagerTest extends PHPUnit_Framework_TestCase {
+
+	public function testDriverMethodReturnsDriverWhenOneIsRegistered()
+	{
+		$dependencies = array(
+			'laravel.session.test' => array('resolver' => function($container)
+			{
+				return new stdClass;
+			})
+		);
+
+		$manager = new Laravel\Session\Manager(new Laravel\Container($dependencies));
+
+		$this->assertInstanceOf('stdClass', $manager->driver('test'));
+	}
+
+	/**
+	 * @expectedException Exception
+	 */
+	public function testDriverMethodThrowsExceptionForUndefinedDriver()
+	{
+		$manager = new Laravel\Session\Manager(new Laravel\Container(array()));
+
+		$manager->driver('test');
+	}
+
+}