Run unittests in CI

.gitlab-ci.yml

 
 stages:
+  - test
   - build
   - deploy
 
+unittest:
+  stage: test
+  image: python:3.7
+  script:
+    - cd app
+    - pip install -r requirements.txt
+    - python manage.py migrate
+    - python manage.py test
+
 build:
   when: manual
   stage: build