Update pytest from 3.0.5 to 3.0.6

Author: pyup-bot

requirements-dev.txt

@@ -16,6 +16,6 @@ pep8==1.7.0 # via flake8
 py==1.4.32 # via pytest
 pyflakes==1.5.0 # via flake8
 pytest-django==3.1.2
-pytest==3.0.5
+pytest==3.0.6
 selenium==3.0.2
 six==1.10.0 # via django-appconf