feat(tox): add basic .gitlab-ci.yml

4 jobs for topic/default/add_tox_new_style in 1 minute and 6 seconds (queued for 29 seconds)
Status Job ID Name Coverage
  Test
passed check-manifest #67940

00:00:21

passed flake8 #67941

00:00:20

passed py27 #67942

00:00:49

passed py3 #67943

00:01:05