Ignore some warning from thirdparty libs

setup.cfg

 [bdist_wheel]
 universal=1
 
-[pytest]
+[tool:pytest]
 python_files=test_*.py *tests.py
 testpaths = tests/
+filterwarnings = 
+    ignore:.*is deprecated.*:Warning:django_webtest.middleware
+    ignore::DeprecationWarning:sorl.thumbnail.base
 
 [flake8]
 exclude = migrations