Merge branch 'maint/44.x'

.travis.yml

@@ -26,6 +26,9 @@ jobs:
     if: tag IS present
     script: tox -e release
     after_success: skip
+  allow_failures:
+  # suppress failures due to pypa/setuptools#2000
+  - python: pypy3
 
 cache: pip
 

tox.ini

@@ -7,6 +7,8 @@ envlist=python
 minversion = 3.2
 requires =
 	tox-pip-version >= 0.0.6
+	# workaround for #1998
+	virtualenv < 20
 
 [helpers]
 # Custom pip behavior