Make Python style traceback as the default one

pytest style of traceback adds additional symbols,
which supposedly makes it prettier to look, but
prevents from parsing easily data collections
(e.g. dicts).
Python style of traceback helps to resolve the issue.

Change-Id: I682a61d74092978cab4f9146c6b8260b20dc0b3e
Related-PROD: #PROD-23832
diff --git a/test_set/cvp-sanity/pytest.ini b/test_set/cvp-sanity/pytest.ini
index a5828a2..abbaba9 100644
--- a/test_set/cvp-sanity/pytest.ini
+++ b/test_set/cvp-sanity/pytest.ini
@@ -1,6 +1,6 @@
 [pytest]
 norecursedirs = venv*
-addopts = -vv --tb=short
+addopts = -vv --tb=native
 
 log_level=WARNING
 log_format = '%(message)s'
diff --git a/test_set/cvp-spt/pytest.ini b/test_set/cvp-spt/pytest.ini
index 0180774..f5c241c 100644
--- a/test_set/cvp-spt/pytest.ini
+++ b/test_set/cvp-spt/pytest.ini
@@ -1,3 +1,3 @@
 [pytest]
 norecursedirs = venv
-addopts = -vv --tb=short --capture=no
\ No newline at end of file
+addopts = -vv --tb=native --capture=no