add # pyup: ignore [ci skip]

Author: alimanfoo

requirements_dev_minimal.txt

@@ -7,4 +7,4 @@ setuptools-scm==3.3.3
 # test requirements
 pytest==5.0.1; python_version > '3.0'
 # don't let pyup change this, needed until we drop support for py27
-pytest==4.6.5; python_version < '3.0'
+pytest==4.6.5; python_version < '3.0' # pyup: ignore