Comment 4 for bug 1802032

Reviewed: https://review.openstack.org/608210
Committed: https://git.openstack.org/cgit/openstack/stx-distcloud/commit/?id=9a976a61c38c22b8465cc84a730686c3138c466b
Submitter: Zuul
Branch: master

commit 9a976a61c38c22b8465cc84a730686c3138c466b
Author: 98k <18552437190@163.com>
Date: Fri Oct 5 10:34:55 2018 +0000

    fix tox python3 overrides

    We want to default to running all tox environments under python 3, so
    set the basepython value in each environment.

    We do not want to specify a minor version number, because we do not
    want to have to update the file every time we upgrade python.

    We do not want to set the override once in testenv, because that
    breaks the more specific versions used in default environments like
    py35 and py36.

    Change-Id: I24b87db5bd80876ff631698350606aa4e23919ee
    Closes-Bug: #1802032
    Signed-off-by: 98k <18552437190@163.com>