Update pytest from 5.2.4 to 5.3.2 (#162)

Author: pyup-bot

dev-requirements.txt

@@ -5,7 +5,7 @@ sphinx-autobuild==0.7.1
 m2r==0.2.1
 pytest-vcr==1.0.2
 pytest-cov==2.7.1
-pytest==5.2.4
+pytest==5.3.2
 codecov==2.0.15
 setuptools==42.0.2
 pre-commit==1.20.0