Merge "Changed minversion in tox to 3.18.0"

Author: Zuul

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-minversion = 2.0
+minversion = 3.18.0
 envlist = py36,py38,pep8
 skipsdist = True
 ignore_basepython_conflict = True
@@ -38,7 +38,7 @@ commands = sphinx-build -W --keep-going -b html doc/source doc/build/html
 [testenv:pdf-docs]
 envdir = {toxworkdir}/docs
 deps = {[testenv:docs]deps}
-whitelist_externals =
+allowlist_externals =
   make
 commands =
   sphinx-build -W --keep-going -b latex doc/source doc/build/pdf