TEST Review can be deleted

[jamalbrowning]

Create TEST so reviews can be deleted.

Example

def test_delete_product(self):
        """
        Ensure we can remove a product.
        """
        # add product
        self.test_get_all_products()

        # remove product
        url = "/products/1"
        data = {"id": 1}
        self.client.credentials(HTTP_AUTHORIZATION='Token ' + self.token)
        response = self.client.delete(url, data, format='json')

        self.assertEqual(response.status_code, status.HTTP_204_NO_CONTENT)

        # get products and verify product was removed
        url = "/products/1"
        self.client.credentials(HTTP_AUTHORIZATION='Token ' + self.token)
        response = self.client.get(url, None, format='json')

        self.assertEqual(response.status_code,
                         status.HTTP_500_INTERNAL_SERVER_ERROR)