Code quality check with tox

.gitlab-ci.yml

@@ -2,20 +2,25 @@ image: python:3.6
 
 stages:
   - test
+  - quality-assurance
 
 before_script:
   - pip install tox
 
-python36:
+py36-django22:
   image: python:3.6
   stage: test
-  script: tox -e py36
+  script: tox -e py36-django22
 
-python37:
+py37-django22:
   image: python:3.7
   stage: test
-  script: tox -e py37
+  script: tox -e py37-django22
 
 linters:
-  stage: test
+  image: python:3.6
+  stage: quality-assurance
   script: tox -e linters
+
+  # Be nice to new contributors, but please use `tox`
+  allow_failure: true