Merge pull request #1107 from python-trio/dependabot/pip/pytest-4.6.3

Author: dependabot-preview[bot]

test-requirements.txt

@@ -44,7 +44,7 @@ pyopenssl==19.0.0
 pyparsing==2.4.0          # via packaging
 pytest-cov==2.7.1
 pytest-faulthandler==1.6.0
-pytest==4.6.2
+pytest==4.6.3
 six==1.12.0               # via astroid, cryptography, packaging, prompt-toolkit, pyopenssl, pytest, traitlets
 sniffio==1.1.0
 sortedcontainers==2.1.0