Drop py3.5 from tempest plugins
As per the community goal drop python2.7 [1], tempest is dropping
py3.5 and asked to drop from its plugins too.
[1]lists.openstack.org/pipermail/openstack-discuss/2020-February/012310.html
Change-Id: I40d40c58a77c58533da543d59cdb4549a1d20d45
diff --git a/tox.ini b/tox.ini
index 3a014bc..ecc7ddf 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
[tox]
minversion = 3.1.1
-envlist = py35,py36,pypy,pep8
+envlist = py36,pypy,pep8
skipsdist = True
ignore_basepython_conflict = True