Pin pytest to latest version 6.2.3

pyup-bot · pyup-bot · commit 9a5a9f38ab7d · 2021-04-04T11:08:49.000+10:00
diff --git a/test-requirements.txt b/test-requirements.txt
@@ -1,2 +1,2 @@
-pytest
+pytest==6.2.3
 pytest-cov
