Add model cookied-bm-contrail with MaaS

Change-Id: I8f29d684a5de003f2f1788cfb8c56a8ef819eae0
diff --git a/tcp_tests/settings.py b/tcp_tests/settings.py
index f90000c..24c6c0b 100644
--- a/tcp_tests/settings.py
+++ b/tcp_tests/settings.py
@@ -59,3 +59,4 @@
 
 PATTERN = os.environ.get('PATTERN', None)
 RUN_TEMPEST = get_var_as_bool('RUN_TEMPEST', False)
+RUN_SL_TESTS = get_var_as_bool('RUN_SL_TESTS', False)