phpunit is not populating fixtures in Laravel 4

I'm trying to add a unit testing framework to an already existing Laravel project. I've read the PHPUnit manual and I'm trying to set up a sqlite environment using .xml datasets to populate the test data and a main migration to create the schema but the actual test data does not seem to be populating into the tables.

I started out adding phpunit and dbunit to the composer.json file and updating them. I added vendor/bin to $PATH so the VM will know where to find it.

I then expanding the existing TestCase class with getConnection(), getDataSet() and setUp() which contains

 class TestCase extends Illuminate\Foundation\Testing\TestCase {

    static private $pdo = null;

    private $conn = null;


    public function setUp() {
        parent::setUp();

        Artisan::call('migrate');

        $this->seed();
    }

    public function createApplication() {
        $unitTesting = true;

        $testEnvironment = 'testing';

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

    public function getDataSet() {
        parent::getDataSet();
    }

    public function getConnection() {
        if ($this->conn === null) {
            if (self::$pdo == null) {
                self::$pdo = new PDO('sqlite::memory:');
            }
            $this->conn = $this->createDefaultDBConnection(self::$pdo, ':memory:');
        }

        return $this->conn;

    }
}

The Illuminate\Foundation\Testing\Testcase I changed to :

abstract class TestCase extends \PHPUnit_Extensions_Database_TestCase {
....
}

This done, I created an XML dataset

<?xml version="1.0" ?>
<dataset>
    <table name="a_table">
       <column>id</column>
       <column>data1</column>
       <column>data2</column>
       <row>
           <value>1</value>
           .....
           .....
       </row>
       <row>
           .....
       </row>
   </table>
</dataset>

I used the artisan convert migrations command to create the schema.

Then I wrote my first test.

class ImportantClassTest extends TestCase {

    /**
     * @author Me
     * 
     * 
     * Tests the functionality of some function
     * @dataProvider ImportantFunctionData();
     */
    public function testthisImportantFunction($an_id,$an_amount,$another_amount,$starting_rows,$expected_rows)
    {
        $this->assertEquals($this->getConnection()->getRowCount('a_table'),$starting_rows);
        $result = ImportantClass::ImportantFunction($an_id, $an_amount);
        $this->assertEquals($another_amount,$result);
        $this->assertEquals($this->getConnection()->getRowCount('a_table'),$expected_rows);
    }

    public function ImportantFunctionData()
    {
        return array(
            array(1337,1000,180,10,10),
            array(1338,3900,900,10,11)
        );
    }

    public function getDataSet()
    {
        return $this->createXMLDataSet(dirname(__FILE__) . '/_files/ImportantFunctionData.xml');
    } }

I added config/testing/database.php :

return array(


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

When I run the test, the migration occurs to create the db in sqlite memory, but the data does not appear to populate. With the row checking I get this error :

1) ImportantClass::testthisImportantFunction with data set #0 (1337, 1000, 180, 10, 10) PDOException: SQLSTATE[HY000]: General error: 1 no such table: a_table

and just the result assertion on it's own

1) ImportantClass::testthisImportantFunction with data set #0 (1337, 1000, 180, 10, 10) Failed asserting that 1000 matches expected 180.

So in neither case does it appear that phpunit is populating the fixtures correctly.

Can anyone see where I'm going wrong?