bitbake: toaster/tests: Update build test

Updated build tests in toaster, added SSTATE_MIRROR to package build, changed build directory and update test order
This builds include the core-minimal-image, on the test enviroment a smaller package was use to run the test for time purposes

(Bitbake rev: af31116f0017912fc5a58a5976c814b6b326985f)

Signed-off-by: Marlon Rodriguez Garcia <marlon.rodriguez-garcia@savoirfairelinux.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/toaster/tests/commands/test_lsupdates.py

@@ -7,12 +7,13 @@
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
+import pytest
 from django.test import TestCase
 from django.core import management
 
 from orm.models import Layer_Version, Machine, Recipe
 
-
+@pytest.mark.order(3)
 class TestLayerIndexUpdater(TestCase):
     def test_run_lsupdates_command(self):
         # Load some release information for us to fetch from the layer index