Dropping the py35 testing

All the integration testing has been moved to
Bionic now[1] and py3.5 is not tested runtime for
Train or stable/stein[2].

As per below ML thread, we are good to drop the py35
testing now:
http://lists.openstack.org/pipermail/openstack-discuss/2019-April/005097.html

[1] http://lists.openstack.org/pipermail/openstack-discuss/2019-April/004647.html
[2]
https://governance.openstack.org/tc/reference/runtimes/stein.html
https://governance.openstack.org/tc/reference/runtimes/train.html

Change-Id: I21640e78f9bb42083e9dae03b484f9be3f4a78ac

.zuul.yaml

@@ -4,7 +4,6 @@
       - horizon-nodejs10-jobs
       - openstack-lower-constraints-jobs-horizon
       - openstack-python-jobs-horizon
-      - openstack-python35-jobs-horizon
       - openstack-python36-jobs-horizon
       - publish-openstack-docs-pti
       - release-notes-jobs-python3

setup.cfg

@@ -16,7 +16,7 @@ classifier =
     Programming Language :: Python :: 2
     Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.5
+    Programming Language :: Python :: 3.6
 
 [files]
 packages =

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = pep8,py27-local,py35-local,py3-dj111-local,eslint,karma-local,docs-local,releasenotes,lower-constraints-local
+envlist = pep8,py27-local,py36-local,py3-dj111-local,eslint,karma-local,docs-local,releasenotes,lower-constraints-local
 minversion = 2.3.2
 skipsdist = True
 
@@ -53,12 +53,6 @@ commands =
   {[testenv:hz-local]commands}
   {[testenv]commands}
 
-[testenv:py35-local]
-basepython = python3.5
-commands =
-  {[testenv:hz-local]commands}
-  {[testenv]commands}
-
 [testenv:py36-local]
 basepython = python3.6
 commands =