Add py35 to trove classifier
Add py35 to trove classifier

Add Python 3.5 as trove classifier to setup.cfg.

We don't run any unit tests but expect that Python 3.5 works.

Change-Id: I231c2beaaf90c7da0185758829b0b9ddb216eba6

openstack/openstack-doc-tools,openstack/openstack-doc-tools