ci: Run builds against 3.5 & 3.6

- ctrl-c ctrl-v from Go

Signed-off-by: David Haynes <dhaynes3@gmu.edu>
3 jobs for 43-python-3 in 25 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed whats-open-py2.7 #2342

00:00:19

passed whats-open-py3.5 #2343

00:00:21

passed whats-open-py3.6 #2344

00:00:24