Non-working Laravel test

config-testing-database.php

<?php

return array(
    'default' => 'sqlite',
    'connections' => array(
        'sqlite' => array(
            'driver' => 'sqlite',
            'database' => ':memory:',
            'prefix' => '',
        )
    )
);

console-output.txt

$ vendor/bin/phpunit
PHPUnit 3.8-dev by Sebastian Bergmann.

Configuration read from /Users/learning/PhpstormProjects/laravel_test/phpunit.xml

.PHP Fatal error:  Call to undefined method User::save() in /Users/learning/PhpstormProjects/laravel_test/app/tests/UserTest.php on line 8
User is Eloquent: YES

Fatal error: Call to undefined method User::save() in /Users/learning/PhpstormProjects/laravel_test/app/tests/UserTest.php on line 8

TestCase.php

<?php

class TestCase extends Illuminate\Foundation\Testing\TestCase {

    public function setUp()
    {
        parent::setUp();
        $this->prepareForTests();
    }

  /**
	 * Creates the application.
	 *
	 * @return Symfony\Component\HttpKernel\HttpKernelInterface
	 */
	public function createApplication()
	{
		$unitTesting = true;

		$testEnvironment = 'testing';

		return require __DIR__.'/../../bootstrap/start.php';
	}

    private function prepareForTests()
    {
        Artisan::call('migrate');
    }

}

UserTest.php

<?php

class UserTest extends TestCase {
    public function testUserNameIsAlwaysUppercase()
    {
        $user = new User();
        print "User is Eloquent: " . ($user instanceof Eloquent ? "YES" : "NO") . "\n";
        $user->save();
    }
}