Changed minversion in tox to 3.18.0

The patch bumps min version of tox to 3.18.0 in order to
replace tox's whitelist_externals by allowlist_externals option:
https://github.com/tox-dev/tox/blob/master/docs/changelog.rst#v3180-2020-07-23

Change-Id: If39d3834724ff3116a2a5ee1ae0974148c339b79

1 files changed, 2 insertions, 2 deletions

diff --git a/tox.ini b/tox.ini
index d05b8d89..52bea255 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 envlist = py38,pep8,cover,api-ref,releasenotes,bandit,fakemodetests
-minversion = 2.0
+minversion = 3.18.0
 skipsdist = True
 
 [testenv]
@@ -21,7 +21,7 @@ commands = find ./trove -type f -name "*.pyc" -delete
            rm -f trove_test.sqlite
            stestr run --serial {posargs}
            stestr slowest
-whitelist_externals = find
+allowlist_externals = find
                       rm
                       bash