Fixes the several problems/errors caused by tox 3

Change-Id: If56cab52b26e5f00ac5738544bdb213a97af073d

tox.ini

@@ -1,7 +1,8 @@
 [tox]
 envlist = pep8
-minversion = 2.0
+minversion = 3.18.0
 skipsdist = True
+ignore_basepython_conflict = True
 
 [testenv]
 basepython = python3
@@ -12,11 +13,15 @@ deps =
     -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/test-requirements.txt
-passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
+passenv =
+    http_proxy
+    https_proxy
+    no_proxy
 
 [testenv:bashate]
 whitelist_externals = bash
 commands = bash -c "find {toxinidir} -not -wholename \*.tox/\* -and \( -name \*.sh -or -wholename \*.d/\* -and -not -name \*.md -and -not -name \*.rst -and -not -name \*.py \) -print0 | xargs -0 bashate -v"
+allowlist_externals = bash
 
 [testenv:pep8]
 setenv =
@@ -25,6 +30,8 @@ commands =
     flake8 {posargs}
     {toxinidir}/tools/run_bashate.sh
     dib-lint
+allowlist_externals = /bin/bash
+                      {toxinidir}/tools/run_bashate.sh
 
 [testenv:venv]
 commands = {posargs}