Pin pytest downstream requirement 'attrs' to latest Py 3.4 supporting version

lovelydinosaur · lovelydinosaur · commit 8b5f2f35610b · 2021-05-06T12:52:00.000+01:00
diff --git a/dev-requirements.txt b/dev-requirements.txt
@@ -1,2 +1,3 @@
 pytest
 pytest-cov>=2.0
+attrs==20.1.0
