Update .gitlab-ci.yml to support new settings

- list env vars
- also update manage.py and wsgi.py to use associated settings
4 jobs for 107-split-settings in 1 minute and 3 seconds (queued for 3 seconds)
Status Name Job ID Coverage
  Test
passed Go-py2.7 #2319

00:00:57

passed Go-py3.4 #2320

00:01:00

passed Go-py3.5 #2321

00:01:00

passed Go-py3.6 #2322

00:01:02

72.0%